# Deep Sky Astrophotography



## jrista (Apr 8, 2014)

The other thread ended up with a bit too much discussion on the topic of astrophotography and the related gear. Figured a new, clean one, dedicated just to the imagery, would be good. 

*Please,* feel free to share your own images as well! (If you already shared some in the old thread, maybe re-share them here, hopefully we can keep this topic free of astrophotography gear and technique related discussion, and just keep it on the images.) 

Here are some of my images, produced with some dedicated astrophotography equipment (german equatorial tracking mount, or GEM, guiding telescope and camera, etc.) All of these were created from mid Feb. 2014 through the end of March. 2014. 

Star Clusters
*The Pleiades (Seven Sisters), in Taurus:*





Original Attempt





Second Attempt (deeper exposures, softer detail due to tracking issues)

*M35 and NGC2158, in Gemini*





Nebula
*Horse Head and Flame Nebulas, In Orion:*





*Orion Nebula (M42 & M43) and Running Man, in Orion:*





*Rosette Nebula, in Monoceros (Unicorn):*




Original Processing





Reprocessed in PixInsight

Galaxies
*M101 (Pinwheel Galaxy), in Ursa Major:*





*M81, M82 and NGC3077, in Ursa Major:*





*M51, in Canes Venatici:*





*Leo Triplet (NGC3628, M65, M66) & NGC3593, in Leo:*


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## TheJock (Apr 8, 2014)

This is incredible stuff mate, I’m dying to try this genre of photography, but last time we had no moon (last weekend) there was a sand/dust storm and the sky was obscured. 
The image of the M101 galaxy is stunning, could you share how you achieved this photograph? I would love to have a bash! 
Ohh, I have the Google Sky Map app on my phone, so I can at least spot the general direction of the galaxies etc!
Thanks in advance.


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## sagittariansrock (Apr 8, 2014)

TheJock said:


> The image of the M101 galaxy is stunning, could you share how you achieved this photograph? I would love to have a bash!





jrista said:


> hopefully we can keep this topic free of astrophotography gear and technique related discussion, and just keep it on the images.



Here is the other thread:
http://www.canonrumors.com/forum/index.php?topic=18435.165


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## jrista (Apr 9, 2014)

@TheJock: Check out the other thread. I've provided a lot of information on the kind of equipment you'll need to get started. We can continue the discussion there.


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## verysimplejason (Apr 9, 2014)

Beautiful Sir! Someday, I dream also to take one. Keep posting these excellent work of yours.


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## Jeffbridge (Apr 9, 2014)

Beautiful captures; excellent series!!


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## jrista (May 28, 2014)

We finally had a couple of clear nights the last two nights here in Colorado. These are the first since the lunar eclipse some five weeks ago now. Gave me the opportunity to image part of the North America nebula in Cygnus.





Equipment:
- Canon EOS 7D (unmodded)
- Canon EF 600mm f/4 L II (image)
- Orion ST80 (guider) + SSAG

Integration (49 subs (3h 40m)):
- 52x270s (4m30s) (95% integrated)
- 67 Darks (divided into three groups, temp matching lights, ~15-20 darks per group)
- 100 Biases
- 30 Flats


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## wsmith96 (May 29, 2014)

You've posted some incredible photographs! My favorite is the horse head nebula. Bravo and please post more when you can.

- Wesley


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## Mt Spokane Photography (May 29, 2014)

Living up in the Northwest, our availability of clear weather is limited to the summer, and then we have a lot of light contamination from Spokane, starting about 10 miles South of us. We are in the country, as far as the neighborhood, but not away from the city light.

I've been up in Northern British Columbia, 100 miles from anything but tiny villages, and its truly amazing what you can see on a clear night. Astrophotography would be a great hobby up there.


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## jrista (May 29, 2014)

Mt Spokane Photography said:


> Living up in the Northwest, our availability of clear weather is limited to the summer, and then we have a lot of light contamination from Spokane, starting about 10 miles South of us. We are in the country, as far as the neighborhood, but not away from the city light.
> 
> I've been up in Northern British Columbia, 100 miles from anything but tiny villages, and its truly amazing what you can see on a clear night. Astrophotography would be a great hobby up there.



Light pollution doesn't have to be a problem these days. I actually shot this only a few miles from Denver, CO. The trick is using a light pollution filter. They don't work as well for galaxies (which are mostly stars, so broad band emissions), but for nebula (which are narrow band emissions), they work wonders. I use the Astronomik CLS, which is one of the better ones for blocking pollutant bands. 

All of my images were shot under light polluted skies using the Astronomik filter. I'm under a yellow zone that, depending on the atmospheric particulates, often turns into an orange zone (I generally judge by whether I can see the milky way or not...if I can faintly see it, then my LP conditions are more yellow-zone, if not, then orange zone. Either way, with an LP filter, you can image under heavily light polluted skies. I know many people who image under white zones.

I agree, though, it's amazing what you can see under dark skies. There is one spot in the north western corner of Colorado that is 100% free of LP of any kind. I want to get up there sometime and see what it's like. You can very clearly see the milky way, so clearly that all the dust lanes show up to the naked eye, and all the larger Messier objects (like Andromeda, Triangulum, etc.) is also visible to the naked eye.


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## Kahuna (May 29, 2014)

Jon,

Absolutely astonishing work. I am cuurently vacationing on a small island in northern Fiji and wish you could all experience 0 LP. Its amazing what the naked eye can see. Unfortunately my hard drive died so I can post photo,s.


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## dochawk (May 29, 2014)

These are amazing. I'm jealous. Gonna try my hand in a big way tonight with a large telescope (60 cm - professionally guided, Mt. Wilson Observatory). We were planning on shooting planets with the 1DX and deep space 60a. Any extra advice would be helpful. (I've read alot over the last few weeks, but always need to learn more)


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## jrista (May 30, 2014)

Thanks, guys!  

@Kahuna, I bet the sky out there is AMAZING! I'm quite envious. I barely remember dark skies as a kid, when LP was much less than it is today, and when we lived pretty far out of town. But I wasn't as observant of the details back then. I really don't even remember what the summer sky milky way looks like under a truly dark sky.

Even if you don't have a camera, you still have eyeballs and a brain! Remember those nights!  



dochawk said:


> These are amazing. I'm jealous. Gonna try my hand in a big way tonight with a large telescope (60 cm - professionally guided, Mt. Wilson Observatory). We were planning on shooting planets with the 1DX and deep space 60a. Any extra advice would be helpful. (I've read alot over the last few weeks, but always need to learn more)



Thanks! 

As for advice, that is probably best left for another thread. Start one, PM me the link, and I'll offer the best bits of advice I have.


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## emag (May 30, 2014)

M109 in Ursa Major, most distant of the Messier objects.

First try with PixInsight, I've been using Deep Sky Stacker & PhotoShop for years, but a trial download of PixInsight converted me pretty quick. I recently revamped my old imaging laptop (Vista) with a SSD and a new video cable for the display and installed AstroTortilla on it. Confirmed AT works fine with some archived images....but don't you know we have a week of rain coming at us. I'd rather subject that laptop to the elements than my i7 Win8.1, which is now my image processing platform so my son can have his desktop back. I like my Newt and SCT's, but the only 'refractor' I'd be interested in is that 600/4L. APO's are nice, but you can't shoot BIF's with one.....


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## traingineer (May 31, 2014)

jrista said:


> We finally had a couple of clear nights the last two nights here in Colorado. These are the first since the lunar eclipse some five weeks ago now. Gave me the opportunity to image part of the North America nebula in Cygnus.
> 
> 
> 
> ...



Superb image of the North America Nebula! (NGC 7000) But could you explain how the nebula "looks" like the continent? ??? Because I can't really see any resemblance between the 2.


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## sjbradbury (May 31, 2014)

Can I post stuff here if it wasn't taken with a Canon?  I've been doing astrophotography for a few years now.

These are taken with a 530mm f/5 telescope, and a camera with a KAF-16803 sensor (4096x4096, 9µm pixel).


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## SoullessPolack (May 31, 2014)

Does anyone have any image samples from a single exposure of deep sky astrophotography, compared with say 60 or 150 or whatever images including dark frames of the same scene? I'm wondering how big of a difference spending all that extra time takes. Many of the images I see are stunning, and I'd like to make my own similar ones, but I'd rather have 70% of the quality and only have to do one image and very little time post processing than 100% quality but hours upon hours of work (not to mention wear and tear on the shutter and mirror mechanism). 

Thank you in advance. Just hoping to see if it's worth it for me to get into this discipline!


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## jrista (May 31, 2014)

Soulless, here are three samples of the same single light frame. Note that the first two have been downsampled by a factor of 6.5x, which has the effect of SIGNIFICANTLY reducing noise. I've included a 1:1 crop to show how much noise there is in one single frame. It is the noise levels that are the primary reason why you really have to take 50, 80, 100 frames and stack them...it's the only way to reduce noise to manageable levels with a DSLR.

With Cooled CCD cameras like Bradbury's KAF-16803, you have significantly less dark current noise due to the sensor being cooled by some -50°C relative to ambient, and less read noise. You don't need to stack as many subs to get a good result with a dedicated CCD, however you DO still need to stack.

Original Out-of-Camera Frame (blue due to optical light pollution filter):





Same frame color-corrected and stretched:





100% crop from frame to show noise:





The last sample here, a you can see, has a completely unacceptable level of noise. The amount of noise drops as the square root of the frames stacked. So, to reduce the noise by a factor of two, you need to stack four subs. However, there is a LOT of noise in a single frame, a 2x reduction in noise isn't remotely close enough. To get a 3x reduction, you need nine frames...to get a 4x reduction, you need 16 frames....to get a 5x reduction in noise, you need at least 25 frames. If you are using a thermally regulated CCD, 25 frames might be getting to the point where noise is low enough to be acceptable..."MIGHT BE GETTING TO". 

For a DSLR, 25 frames is never enough (even when the outside nighttime temps are around 0°C). At 50 frames, you reduce noise by 7x. In my experience and opinion, for a DSLR like the 7D at spring and fall nighttime temperatures, 50 frames is the MINIMUM. During summer nighttime temps, at least 81 frames, but 100 (a full 10x reduction in noise) is preferable. I effectively need to double my exposures to reduce the noise in my North America nebula to a level I would deem acceptable and aesthetically pleasing.


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## traingineer (Jun 5, 2014)

My first 4th and currently best AP image I've made, and the first with a mount!


First image contains Vega

Second image is one of the many light frames used for the final image:


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## R1-7D (Jun 5, 2014)

Just think about how much better these photos would be with more dynamic range! Oh wait...wrong thread again. Damn.


Beautiful shots everyone!


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## Mr_Canuck (Jun 18, 2014)

This is so way beyond me. But beautiful to look at. Congrats on figuring all this out. So complex for my level of patience.


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## jrista (Jun 20, 2014)

More Cygnus. I really love this region of sky, it's amazing. Tonight I've been getting image time on IC1318, IC1318B which are large nebulous regions, and NGC6910 which is a nice little open cluster nearby. The full frame of the 5D III is JUST AMAZING. It's more than twice as big as the 7D frame, and the images, once processed, are pretty stunning. 

This is my first pass at processing a single-frame image of North America and Pelican nebulas in Cygnus, near the top star. Not entirely satisfied with it...I'd like to stretch it more, bring out some more detail, but I need to get a better handle on noise and color correction (a lot of the color correction routines end up making things noisier as they end up nuking most of the green color channel.) 







Usually, getting this entire region requires a 4-panel mosaic with the smallish CCD sensors you can usually find for a reasonable price. Only those with the big money can get comparable full frame CCD cameras...which usually cost about $10,000 or more. I've got a cold box in the works for the 5D III, which should help get my dark current levels under control, and help me get better, deeper, less noisy subs (although still not as good as a cooled CCD...my cold box will probably only get me down to around -10°C, where as a good CCD can get you down to -25°C. With dark current doubling/halving every 5.8°C, a CCD is going to be about about 2.6x less noisy (and even better than that, really, as a mono CCD has a higher fill factor, no sparse color spacing, and CCDs designed for astro tend to have lower dark current to start with...)


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## jrista (Jun 20, 2014)

Bradbury and emag, great images! I love the veil, wonderful detail there.


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## Click (Jun 20, 2014)

jrista said:


> More Cygnus. I really love this region of sky, it's amazing. Tonight I've been getting image time on IC1318, IC1318B which are large nebulous regions, and NGC6910 which is a nice little open cluster nearby. The full frame of the 5D III is JUST AMAZING. It's more than twice as big as the 7D frame, and the images, once processed, are pretty stunning.
> 
> This is my first pass at processing a single-frame image of North America and Pelican nebulas in Cygnus, near the top star. Not entirely satisfied with it...I'd like to stretch it more, bring out some more detail, but I need to get a better handle on noise and color correction (a lot of the color correction routines end up making things noisier as they end up nuking most of the green color channel.)



Awesome. Great shot jrista


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## Mr Bean (Jun 20, 2014)

sjbradbury said:


> Can I post stuff here if it wasn't taken with a Canon?  I've been doing astrophotography for a few years now.
> 
> These are taken with a 530mm f/5 telescope, and a camera with a KAF-16803 sensor (4096x4096, 9µm pixel).


Wow, stunning. Love the detail 

What region of the sky?


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## Mr Bean (Jun 20, 2014)

jrista said:


> More Cygnus. I really love this region of sky, it's amazing. Tonight I've been getting image time on IC1318, IC1318B which are large nebulous regions, and NGC6910 which is a nice little open cluster nearby. The full frame of the 5D III is JUST AMAZING. It's more than twice as big as the 7D frame, and the images, once processed, are pretty stunning.
> 
> This is my first pass at processing a single-frame image of North America and Pelican nebulas in Cygnus, near the top star. Not entirely satisfied with it...I'd like to stretch it more, bring out some more detail, but I need to get a better handle on noise and color correction (a lot of the color correction routines end up making things noisier as they end up nuking most of the green color channel.)
> 
> ...


Beautiful image jrista. What 'scope or lens are you using?


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## traingineer (Jun 21, 2014)

jrista said:


> More Cygnus. I really love this region of sky, it's amazing. Tonight I've been getting image time on IC1318, IC1318B which are large nebulous regions, and NGC6910 which is a nice little open cluster nearby. The full frame of the 5D III is JUST AMAZING. It's more than twice as big as the 7D frame, and the images, once processed, are pretty stunning.
> 
> This is my first pass at processing a single-frame image of North America and Pelican nebulas in Cygnus, near the top star. Not entirely satisfied with it...I'd like to stretch it more, bring out some more detail, but I need to get a better handle on noise and color correction (a lot of the color correction routines end up making things noisier as they end up nuking most of the green color channel.)
> 
> ...


Stunning image!

Are you also going to remove the IR/UV cut filter from the 5D? ;D


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## jrista (Jun 21, 2014)

Thanks, guys.  

Traingineer: I have no plans to mess with the 5D III. I use it for my bird, wildlife, and landscape photography, so I don't want to mess with it's ability to produce high quality, accurate color. I plan to buy a cooled mono Astro CCD soon enough, with a full set of LRGB and narrow band filters, which will trounce anything a modified 5D III, 6D, or any other modded DSLR could do. I expect, in the long run, to have a few cooled astro CCD cams. Different sensor sizes and types are useful for different things, some have huge sensors with lower sensitivity great for ultra wide field stuff, others have small sensors with insanely high sensitivity (77-90% Q.E.), great for deep narrow band imaging. 

Bean: I use my Canon EF 600mm f/4 L II lens as a telescope right now. 

Here is another image from Cygnus. Just took the subs for this last night, and just finished nearly six hours worth of integration/stacking and processing. This is the Sadr region of Cygnus, the close neighboring region to the North America/Pelican nebulas I shared before. 






There are multiple objects in this region. The Gamma Cygni region, comprised of IC1318 A, B, and C, also called the Butterfly Nebula by some, is in the lower middle. This one field also contains two open clusters, M29 and NGC6910. The bright star is Sadr, one of the primary stars that make up the constellation Cygnus itself. A big dust lane (unnamed, as far as I can tell) stretches through the center. A small double star near the lower right of that dust lane is also a reflection nebula...light from the blue star of the pair (barely discernible here) reflects off the dark dust. Another reflection nebula can be found in the upper left region just on the border of one of the darker areas (again too small to really be seen here).

As with most of my images, I was only able to gather about 1/3rd of the total subs I needed to get the best quality. All of my images have around 35-50 individual frames (subs) integrated. I need at least 100 subs to reduce noise to an acceptable level (100 subs averaged together reduces noise by SQRT(100), or 10x), and these days, with summer nighttime temps in the 70s, I probably need to reduce my noise levels by twice that. Problem is, to reduce noise by 20x, I would need 400 subs!!  Hope to get some time this weekend to start building my cold box. I received my copper plate a couple days ago...so I can solder it together and put some insulation around it. Peltiers and voltage regulator are still on the way, and I need see if I can pull apart this indoor/outdoor thermometer to get myself a temperature sensor and readout screen that I can embed into the box. I'm hoping to be able to cool my camera to around -10°C. Compared to the 30-35°C it runs at right now, I should be able to reduce dark current noise by 6-7x.


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## jrista (Jun 30, 2014)

Another one, again from the Cygnus region. This massive region of our galaxy is just PACKED with amazing nebula, most of which are part of the monstrous Cygnus Molecular Cloud.

This time, Veil Nebula. Thought to be a remnant of a supernova, it certainly has some of the most intricate and delicate looking detail I've yet seen in a nebula. It's a bi-colored set of hydrogen-alpha filaments (red) veiled in oxygen sheathes (blue). 






Going to work on getting some more data for this tonight, and I may be able to extract even more detail.


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## NancyP (Jul 14, 2014)

OOO! VERY nice, jrista. I love a good M51 and M101. Horsehead N. is really nice. 
I live in the middle of a city (white zone), but can reach an orange area, Brommelsiek Astronomy Park, in 40 minutes. One of the goofy things about the park is that there is a civil aviation airport right across the river - trails galore, blinkety-blink.


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## niteclicks (Jul 16, 2014)

Thanks Jrista for starting this thread it made finally get started setting my stuff back up. I haven't set my mount up in 4 years, moved and a permanent setup has always been on the to do list (but at the bottom). The long 4th weekend gave me time to unpack and setup temporally to tryout were I might want a permanent mounting. This is a wide field (about 75% crop) of the area around the Trfid and Lagoon nebulae. This is about the southern edge of my usable sky were I have it now. 84 frames at 800 iso, 30sec , 300 2.8l is , 5DIII, on an Atlus EQ-G processed with Images Plus. Alignment needs work but it has mostly been cloudy since.


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## Click (Jul 16, 2014)

Very nice shot niteclicks.

Guys, I'm really impressed by your pictures.


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## niteclicks (Jul 16, 2014)

Thanks Click, I really enjoyed getting out to take this.


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## traingineer (Jul 17, 2014)

niteclicks said:


> Thanks Jrista for starting this thread it made finally get started setting my stuff back up. I haven't set my mount up in 4 years, moved and a permanent setup has always been on the to do list (but at the bottom). The long 4th weekend gave me time to unpack and setup temporally to tryout were I might want a permanent mounting. This is a wide field (about 75% crop) of the area around the Trfid and Lagoon nebulae. This is about the southern edge of my usable sky were I have it now. 84 frames at 800 iso, 30sec , 300 2.8l is , 5DIII, on an Atlus EQ-G processed with Images Plus. Alignment needs work but it has mostly been cloudy since.



Fantastic image, niteclicks!


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## niteclicks (Jul 17, 2014)

Thanks traingineer, 
I have alot of projects planed for this combo ( 5DIII and 300) , My favoite night sky is now though January.


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## jrista (Aug 31, 2014)

niteclicks said:


> Thanks Jrista for starting this thread it made finally get started setting my stuff back up. I haven't set my mount up in 4 years, moved and a permanent setup has always been on the to do list (but at the bottom). The long 4th weekend gave me time to unpack and setup temporally to tryout were I might want a permanent mounting. This is a wide field (about 75% crop) of the area around the Trfid and Lagoon nebulae. This is about the southern edge of my usable sky were I have it now. 84 frames at 800 iso, 30sec , 300 2.8l is , 5DIII, on an Atlus EQ-G processed with Images Plus. Alignment needs work but it has mostly been cloudy since.



You are welcome! I'm glad your participating. Your image is excellent! I've tried to image that target a couple times myself, but my view of the southern sky from my back yard is nearly completely blocked, and I have never been able to get the necessary subs. Your detail and color are great for 30-second subs, too! The f/2.8 aperture must be a DREAM! 



Here is one of my latest. This time, it's Crescent nebula...also, as you might have guessed, in Cygnus. Cygnus is moving along pretty early on in the night now, crossing the meridian by about 11pm now, so unless I can figure out how to get some good imaging time on Tulip and/or Propeller nebulas (both also in the Cygnus molecular clouds), I may switch to a different target soon. 

This image took a LOT of work. I've had to fight some technical issues with my tracking, which was actually caused by a few different things combined into one hellish problem. I also had persistent weather (it's been a COLD summer...temperatures are often in the 70's or below for days at a time, even as long as a week once...when usually we have temperatures in the mid to high 90's with more than a handful of days over 100), which has cut out a LOT of sky time. 

Anyway, persistence finally paid off, allowing me to image Crescent Nebula, which itself is pretty well known...but also pull in a lot of the background nebulosity detail from the extensive molecular cloud in the Cygnus region of one of our galactic arms:






The Crescent itself is quite complex, and actually has a very faint outer shell of mostly oxygen-based gasses that glows a faint blue (usually too dim for a DSLR to see, and generally requires some deep OIII narrow band exposure to bring it out...but I managed to reveal a little bit of it here):






Processed with PixInsight and Photoshop CC+Carboni's Astronomy Actions. See the full size version here:


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## kkelis (Aug 31, 2014)

Dont know if you can call this deep sky astrophoto but here is my version of andromeda
Untracked/unguided 5sec single shot. 200mm f/2.8 iso 6400


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## Don Haines (Aug 31, 2014)

kkelis said:


> Dont know if you can call this deep sky astrophoto but here is my version of andromeda
> Untracked/unguided 5sec single shot. 200mm f/2.8 iso 6400


Nice... Proof that you don't need insane amounts of gear to get started....


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## Click (Aug 31, 2014)

Don Haines said:


> kkelis said:
> 
> 
> > Dont know if you can call this deep sky astrophoto but here is my version of andromeda
> ...



+1 

Well done kkelis.


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## jrista (Sep 2, 2014)

kkelis said:


> Dont know if you can call this deep sky astrophoto but here is my version of andromeda
> Untracked/unguided 5sec single shot. 200mm f/2.8 iso 6400



Definitely deep sky. Nice results for a single shot. Especially only FIVE SECONDS!  Well done.


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## jrista (Sep 4, 2014)

*Elephant Trunk Nebula*

Managed to rip this one out relatively quickly, compared to how long it usually takes me. Thanks to a several-day break in the weather, I imaged all night for three nights in a row, gathered 130 subs, and integrated 116 of them (nearly 10 hours of exposure time).







My deepest exposure yet, by a long shot. Elephant Trunk is a very faint nebula, compared to most of the ones I've been imaging lately. So it needed more exposure time than normal (I usually get 30-50 subs, maybe 4-5 hours, sometimes a little more than that.) I'm pretty happy at how the dust lanes came out...I usually barely get any of that. 

Full size:







I posted a blog on all my Cygnus images from this summer, including some close-up crops of interesting regions:

http://jonrista.com/2014/09/03/the-cygnus-molecular-clouds/


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## Click (Sep 4, 2014)

Awesome shot Jon. Nice work.


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## traingineer (Sep 5, 2014)

jrista said:


> *Elephant Trunk Nebula*
> 
> Managed to rip this one out relatively quickly, compared to how long it usually takes me. Thanks to a several-day break in the weather, I imaged all night for three nights in a row, gathered 130 subs, and integrated 116 of them (nearly 10 hours of exposure time).
> 
> ...



Another fantabulous image!


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## jrista (Sep 26, 2014)

traingineer said:


> Awesome shot Jon. Nice work.





traingineer said:


> Another fantabulous image!



Thanks, guys.  Glad you like. One of my best so far. Data on that one was so good. 

I'm trying a new technique. I used an Astronomik CLS filter most of the year, but it is making it really hard to get images quickly. I have so few clear nights, and I need to image for several nights to get enough subs to produce the kind of quality I got in the Elephant Trunk...that I'm trying to image without the CLS filter now. It results in more complex work in post, but...if you can work through it, you get stuff like this:






Compare that to my first two attempts at Pleiades from the original post of this thread.  One thing I really do love about the 5D III? It's huge full frame...has a really wide field, which is just awesome for images like this.


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## verysimplejason (Sep 26, 2014)

jrista said:


> traingineer said:
> 
> 
> > Awesome shot Jon. Nice work.
> ...



Beautiful!!! Been a fan of your shots Jrista. Can you tell me any starting cheap kit I can use for Astrophotography? Right now, I have some cheap but decent long lenses like 100mm F2.8 Macro, 70-300mm IS USM. For starters, do I need to buy more? Thanks! BTW, I'm using Canon 6D.


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## weixing (Sep 26, 2014)

jrista said:


> traingineer said:
> 
> 
> > Awesome shot Jon. Nice work.
> ...


Hi,
I assume this is taken by 5D3... Did you mod your 5D3?? 

Have a nice day.


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## jrista (Sep 26, 2014)

*Unmodded *Canon 5D III, with 600mm f/4 L II lens. A big part of getting this kind of result is the software I use to process: PixInsight. Powerful, powerful tool.

I use an Atlas EQ-G tracking mount, along with a specific set of rings and dovetails to hold the lens onto the mount. I'll post some photos of my current setup in another thread, so those of you interested in getting started can get an idea of where I'm at, and what options there are at a lower cost.


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## weixing (Sep 26, 2014)

jrista said:


> *Unmodded *Canon 5D III, with 600mm f/4 L II lens. A big part of getting this kind of result is the software I use to process: PixInsight. Powerful, powerful tool.
> 
> I use an Atlas EQ-G tracking mount, along with a specific set of rings and dovetails to hold the lens onto the mount. I'll post some photos of my current setup in another thread, so those of you interested in getting started can get an idea of where I'm at, and what options there are at a lower cost.


Hi,
Your sky must be very good to get that result... 

By the way, you said you previously use the Astronomik CLS filter, how to you solve the colour shift issue?? Last time I use the CLS filter as my area light pollution is very serious, but had big problem solving the colour shift issue... :-[ 

Have a nice day.


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## niteclicks (Sep 26, 2014)

Jrista,One of the best I have seen of this area (you should submit it for the astronomy picture of the day). There is so much more blue in this area compared to the rest of the sky I could see how the cls might interfere with the fainter stuff. I use an IDAS and will have to try without it (if I ever get a clear night). Weixing, just set a custom white balance with the filter in place during the daytime, you can also use this time to take your flats , if you use them.


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## jrista (Oct 22, 2014)

niteclicks said:


> Jrista,One of the best I have seen of this area (you should submit it for the astronomy picture of the day). There is so much more blue in this area compared to the rest of the sky I could see how the cls might interfere with the fainter stuff. I use an IDAS and will have to try without it (if I ever get a clear night). Weixing, just set a custom white balance with the filter in place during the daytime, you can also use this time to take your flats , if you use them.




Hmm, I hadn't thought of that, APOD. I gathered some more subs for the Pleiades image. I think I want to get one or two sessions more, to get better control over noise and maybe improve the quality of the dust, then I'll submit to APOD.


The blue is just those stars. All blue giants.  A little ways down towards the eastern horizon you find Taurus, which has a giant orange star. The faint dust is in that region as well, so the whole area takes on a whole different tone. (I don't think I could pick up the IFN in Taurus...I should try some time, see what I get.)


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## jrista (Oct 22, 2014)

weixing said:


> jrista said:
> 
> 
> > *Unmodded *Canon 5D III, with 600mm f/4 L II lens. A big part of getting this kind of result is the software I use to process: PixInsight. Powerful, powerful tool.
> ...




Actually, it's pretty bad. :\ I'm on the border between a red and orange zone. Sometimes the skies are really bad, sometimes they are fairly decent and I can just barely, faintly see the milky way.


I just integrate like a nutcase.  And I think the brightness of the Pleiades stars brightens the nearby dust enough for me to pick it up. Man, it would be so amazing to image this under blue zone skies.



weixing said:


> By the way, you said you previously use the Astronomik CLS filter, how to you solve the colour shift issue?? Last time I use the CLS filter as my area light pollution is very serious, but had big problem solving the colour shift issue... :-[




The CLS doesn't necessarily cause a color shift. It blocks certain frequencies of light, so they simply are not in the data to start with. Color in astrophotography is a rather fluid thing. There are all kinds of light sources out there, not just stars, but various kinds of gasses, each of which emit light in different very narrow bands. 


I use the CLS when I'm imaging nebula. Most nebula, gaseous emission nebula, emit light in several primary narrow bands, depending on the composition of the nebular clouds. There is Hydrogen, Oxygen, Sulfur, Nitrogen, and a few other gasses. Hydrogen and Oxygen are the most prominent, Hydrogen by far the most prevalent in the skies overall. When you use a CLS filter, or an IDAS filter, or something like that, your blocking out the frequency bands that include light pollution (primarily, sodium and mercury vapor lamps), and passing the blue and red ranges that include H-alpha, H-beta, O-II O-III, N-II & S-II. That lets you pick up the nebula, and when your imaging nebula, that's what you want.


I imaged the Pleiades without the filter, because the nebula around those stars is a reflection nebula. It's not emitting light, it's reflecting light. The CLS filter would have blocked out a good chunk of that light in the greens, which would have resulted in a "color shift". I was able to get away with not using a filter thanks to some of the advanced processing features of PixInsight. It has background extraction capabilities, which I can use to identify any excess light introduced by light pollution, and remove it. It can be extremely difficult to do, especially on an image like my Pleiades...you have to make sure you sample true "background sky", and not any nebula, otherwise that part of the nebula will be factored into the extraction and likely eliminated. It took me a couple days of fiddling to finally extract the background sky well enough for the dust to show...and I'm still not happy with it.


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## jrista (Oct 22, 2014)

Another image, again without the Astronomik CLS filter. This one was an easier target than the Pleiades: Andromeda Galaxy, actually the full complex of M31, M32, and M110. Processing on this was a little easier, however getting color into the core is a challenge (still working on it):


[font=verdana, arial, helvetica, sans-serif]



[/font]

[font=verdana, arial, helvetica, sans-serif]Integration of 74x150s (3hrs) sub frames. Stacked with DSS, processed with PixInsight and Photoshop.[/font]


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## msm (Oct 22, 2014)

jrista said:


> Another image, again without the Astronomik CLS filter. This one was an easier target than the Pleiades: Andromeda Galaxy, actually the full complex of M31, M32, and M110. Processing on this was a little easier, however getting color into the core is a challenge (still working on it):
> 
> 
> [font=verdana, arial, helvetica, sans-serif]
> ...



That and the Pleiades photo are really impressive pictures, what sort of lens you need for that?


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## jrista (Oct 22, 2014)

msm said:


> That and the Pleiades photo are really impressive pictures, what sort of lens you need for that?




Thanks.  I use my EF 600mm f/4 L II right now, which doubles as a very high end telescope. It's similar in IQ to the Officina Stellare Hiper APO 150mm, which is about $11,500.


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## Mickat (Oct 22, 2014)

hey Jrista, 

How do you find the Orion ST80ED and camera for tracking? Is the 400mm focal length enough?

I need to bite the bullet on something for tracking but in terms of the camera, I am looking towards more the Lodestar X2 but in terms of ED80's for guidescope there's a few to choose from. 

Skywatcher Synguider is a standalone guider that a few people I know have them and have had some good results in tracking. I've seen some guys doing 15min exposure with it and a Canon Dslr, I couldn't say much about image quality as I didn't really look too hard at their final results.

I've got 2 telescopes, a Celestron EdgeHD 11" CGEM DX and a Celestron CPC 9.25.

The edgeHD will be used for imaging once I pull my finger out and buy stuff for it. I will most likely end up getting a Fastar adaptor at some point for the front of the scope bringing it down to an F2, microfocuser and dovetails for the guidescope. At this stage I will just use my 5D3 for imaging. 
I make the worst astronomer as I am a night shift worker.  

Have you ever considered a high end refractor telescope?


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## meywd (Oct 22, 2014)

Amazing photos jrista, i am only starting astrophotography with hope of learning the sky while shooting the milky way, don't have a telescope, but a friend took this photo with his using my 600D.


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## Maximilian (Oct 22, 2014)

jrista said:


> Another image, again without the Astronomik CLS filter. This one was an easier target than the Pleiades: Andromeda Galaxy, actually the full complex of M31, M32, and M110.


Really Beautiful. Congrats.
I love those astro pictures that start to become three dimensional.


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## kkelis (Oct 22, 2014)

I did a timelapse video which features Andomeda and Orion. Skip to 5:25 if you care to watch it.
Not bad i believe for 5 sec exposures. 6 seconds for Orion but there is a bit of star trailing.

https://www.youtube.com/watch?v=FDv7laP1G54


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## jrista (Oct 24, 2014)

Mickat said:


> hey Jrista,
> 
> How do you find the Orion ST80ED and camera for tracking? Is the 400mm focal length enough?




I don't actually use the ST80ED, I just use the basic ST80, the real cheap one. For guiding, all I care about are the stars, and once the ST80 is focused, they are good enough for guiding. 



Mickat said:


> I need to bite the bullet on something for tracking but in terms of the camera, I am looking towards more the Lodestar X2 but in terms of ED80's for guidescope there's a few to choose from.
> 
> 
> Skywatcher Synguider is a standalone guider that a few people I know have them and have had some good results in tracking. I've seen some guys doing 15min exposure with it and a Canon Dslr, I couldn't say much about image quality as I didn't really look too hard at their final results.




The Lodestar X2 is real nice, at 77% Q.E. My recommendation for a guide camera, however, is the QHY5L-II. The Lodestar uses a Sony sensor, the QHY5L-II uses an Aptina sensor, and it has 74% Q.E. I recommend the QHY instead of the Starlite guider because it can be used for planetary imaging as well. It's got a nice high sensitivity, high resolution mono sensor that is capable of imaging up to a couple hundred frames a second with the central 320x240 pixel area (which, when your imaging planets, is often all your going to be able to use anyway, even with pretty high magnification.) The Lodestar's cannot be used as planetary imagers. They are better guiders, I think, but less versatile. I use the QHY myself, and I'll be getting an RC-type scope soon here to do planetary (and lunar) imaging with it. 


As for the Synguider, that's like Celestron's Nexguide. It might even be the same technology in a different package. Those are fully self contained guiders. Personally, I try to steer people away from those. If you absolutely do not have the option of using a laptop, ever, then a Synguide or Nexguide is probably the only guiding option. Everyone images with a laptop at the very least these days (I use a 40' USB booster cable and powered USB hub to image from my desktop that I'm using right now.) Using PHD2 with a standard guider is vastly superior to using something like a Synguider IMO. Far more control, which you will really need if you ever want to image at a higher resolution, or at narrower apertures. 




Mickat said:


> I've got 2 telescopes, a Celestron EdgeHD 11" CGEM DX and a Celestron CPC 9.25.
> 
> The edgeHD will be used for imaging once I pull my finger out and buy stuff for it. I will most likely end up getting a Fastar adaptor at some point for the front of the scope bringing it down to an F2, microfocuser and dovetails for the guidescope. At this stage I will just use my 5D3 for imaging.
> I make the worst astronomer as I am a night shift worker.



The EdgeHD 11" is a very nice scope. It's going to be difficult to use, though. To do imaging with it, you are going to need a very hefty mount. The ones that Celestron sells it with are barely adequate. Skilled imagers have made do, and can produce some great images, but it's very challenging. You will definitely need to use OAG (off-axis guiding), so read up on how to get the right spacing in the imaging train. SCTs have certain issues that make them less than ideal for deep sky imaging, such as mirror flop. They can be superb for planetary imaging, and something like the 11" is going to resolve a TON of detail, and with a high mag barlow, you could get close to 10,000mm for some serious magnification. 


I'd recommend starting with the CPC 9.25. The smaller scope is easier to manage, easier to guide, just easier to deal with overall. It will give you a chance to get the hang of things without all the frustrations that come with getting good enough tracking for an 11" aperture scope. It will be more forgiving of seeing (you'll need very very good to excellent seeing conditions to use the 11" effectively, otherwise your just throwing away any potential increase in resolving power that the larger aperture offers because seeing will be limiting you.) The 9.25 is also going to be lighter weight, so you can get away with using a lesser mount. I wouldn't recommend anything less than a mount with a capacity of at least 60lb for imaging with the 11", 100lb would be better. You just need the stability to actually benefit from that kind of resolving power. 


The Orion HDX110 is, IMO, the best option for using scopes 11" and larger...but it's decidedly not very portable. The next best option, if you can scrounge up the money, would be the Astro-Physics Mach1 GTO. That's a true high end mount, and with proper PEC could be used unguided for shorter subs (maybe up to 10 minutes). It's got a 45lb rated capacity, however unlike most lower end mounts, that capacity is an imaging capacity, not a visual observing capacity. The Mach1 is very highly portable, I think it may even be lighter (when broken down, lightest part) than my Atlas EQ-G, which makes it pretty much top dog if your plan to visit dark sites on a frequent basis. 



Mickat said:


> Have you ever considered a high end refractor telescope?




I have a high end refractor.  The 600mm f/4 L II has one of the flattest fields with excellent corner performance. I've looked at the quality from a lot of refractors, a whole lot, and very few achieve the IQ that my 600mm lens does, and most do it at a slower f-ratio. For those that achieve similar IQ at around an f/4 f-ratio, you have to spend about as much, or even significantly more, than I did on the 600mm, so it's a wash. I also have some versatility that you don't generally get with a normal refracting telescope...I can attach the 1.4x or 2x TCs and increase my focal length/imaging scale if I need to.


I actually recommend the Canon 300mm and 600mm L series lenses a lot. I think they are some of the best "telescopes" you can get for the price, given how fast they are. You lack some flexibility when using Canon lenses...you cannot use standard focusers, you don't have any backfocus, so you cannot use things like OAG for better guiding. But for the most part, at the image scales you normally have with these lenses, guiding with an independent guide scope is fine up to around 15 minutes.


If I was ever to buy a "real" refractor, it would probably be the Takahashi FSQ106. That puppy is one of the few that has a similarly flat field, however it has it because it has an 88mm image circle. For most dedicated astro CCD imagers, you use a TINY portion of that giant image circle, so the field is exceptionally flat. The large image circle allows you to use either a reducer or extender, which reduces the image circle to 44mm. You lose corner performance when doing that, however, but it's still quite usable. The large 88mm image circle is also compatible with big imagers, like the 56mm diagonal square KAF-16803 based CCD cameras. (There aren't many scopes that can handle those huge imagers...RCOS and PlaneWave make some, but they are exceptionally expensive. I think AstroTech has one or two new Ritchey-Chretien Truss scopes that have 65-70mm image circles, but even those are some seven grand or so.)


I will probably be getting the AstroTech 8" RC telescope soon here. I want something with a longer focal length for galaxy imaging and planetary imaging, and the AT8RC is only $895.


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## jrista (Oct 24, 2014)

meywd said:


> Amazing photos jrista, i am only starting astrophotography with hope of learning the sky while shooting the milky way, don't have a telescope, but a friend took this photo with his using my 600D.




Looks great! Slap that telescope on an equatorial tracking mount, and you'll be amazed what you can do (although Orion is a deceptively challenging subject, due to it's massive dynamic range...the core around Trap blows out entirely well before you even begin to start getting any useful detail on the surrounding dust detail.) Andromeda is probably an easier target, still bright but not quite nearly as bright as Orion nebula.


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## jrista (Oct 24, 2014)

Maximilian said:


> jrista said:
> 
> 
> > Another image, again without the Astronomik CLS filter. This one was an easier target than the Pleiades: Andromeda Galaxy, actually the full complex of M31, M32, and M110.
> ...




Thanks. Pretty happy with how this one turned out...definitely got some of that sense of three dimensions in there, which was actually more challenging than it sounds.


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## jrista (Oct 24, 2014)

kkelis said:


> I did a timelapse video which features Andomeda and Orion. Skip to 5:25 if you care to watch it.
> Not bad i believe for 5 sec exposures. 6 seconds for Orion but there is a bit of star trailing.
> 
> https://www.youtube.com/watch?v=FDv7laP1G54




Good stuff! Damn good indeed for such short exposures. What camera did you use?


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## jrista (Oct 24, 2014)

Partial solar eclipse from today. Started at 3:20pm, continued until sunset. I imaged through the central period, up to peak and a little after. The sun was too bright before and after that to really image it properly, as I was just using my 10-stop ND filter and f/22 or narrower.  


Nice big cluster of sun spots just below center, though. (Note, this image is big, so you can see the sunspot detail. Also look at the periphery of the sun for some surface structure detail.)









Next time, I have to have a proper solar filter handy, or maybe even a Lunt solar telescope.


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## Click (Oct 24, 2014)

That's a cool shot Jon. 8)


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## kkelis (Oct 24, 2014)

jrista said:


> kkelis said:
> 
> 
> > I did a timelapse video which features Andomeda and Orion. Skip to 5:25 if you care to watch it.
> ...



My 6D with 70-200 f/2.8 MKII at iso 6400. Very dark sky - you could spot Andromeda with the naked eye


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## weixing (Oct 24, 2014)

jrista said:


> msm said:
> 
> 
> > That and the Pleiades photo are really impressive pictures, what sort of lens you need for that?
> ...


Hi,
Hmm... I thought most super telephoto lens are not as good as telescope for imaging... how's the edge performance of the EF 600mm F4 L II??

Anyway, I saw my friend's 130mm f6 StarFire and it's super sharp right to the edge, but the waiting list is 7 to 10 years...  

Have a nice day.


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## kkelis (Oct 24, 2014)

jrista said:


> Partial solar eclipse from today. Started at 3:20pm, continued until sunset. I imaged through the central period, up to peak and a little after. The sun was too bright before and after that to really image it properly, as I was just using my 10-stop ND filter and f/22 or narrower.
> 
> 
> Nice big cluster of sun spots just below center, though. (Note, this image is big, so you can see the sunspot detail. Also look at the periphery of the sun for some surface structure detail.)
> ...



That sunspot is HUGE!!! it must be 10 times the size of the Earth. Is that with the 600mm?

Here is mine from last year solar eclipse. 

3/11/2013 15:54

Partial Solar eclipse as seen from Limassol,Cypus

Canon 600D + 70-200/f2.8 is II + 2xTC + UV Filter + CPL Filter + 10 stop ND Filter — in Limassol, Cyprus.


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## yorgasor (Oct 28, 2014)

I botched my eclipse photos. It was right at sunset on the east coast, I had to drive around a bit before I finally found a place with a low enough view to see the sun during the eclipse, and even then I just had a couple minutes to try and dial things in. I should've planned ahead a little better, and I should've experimented with my equipment ahead of time. Anyway, I got so frustrated with my results, I went out the next day to see what kind of sun shots I could get when I wasn't rushed.



Sun - Single Mylar, Astronomik CLS filter by yorgasor, on Flickr

I tried various versions on this before I finally got a photo I was happy with. I first took some mylar from an emergency blanket. I cut a big rectangle, folded it in half, and wrapped it around this Nikon 300mm f/2.8 AIS lens, and had a 2x Canon Extender III. With the mylar doubled up, I had a difficult time getting a fast enough shutter speed, and the aperture was wide open. The double layer of mylar also inhibited some clarity.

Then I tried a single layer of mylar, but then the sun was too bright. I had to dial down the aperture to f/22 (with the 2x extender, f/44!) and 1/8000 on the shutter speed. This also inhibited clarity. Then I got an idea to use my Astronomik CLS XL clip filter. That let me bring my aperture down to f/11 and 1/8000th. This gave the moon a strong blue cast that needed a lot of post-processing to trim down. But the result was a very clear image of the sun that I was quite pleased with. I just didn't get it all worked out in time for the eclipse 



Homemade Solar Eclipse Filter by yorgasor, on Flickr


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## jrista (Oct 28, 2014)

weixing said:


> jrista said:
> 
> 
> > msm said:
> ...




As I stated, the 600/4 II has stellar corner performance. The field is extremely flat, a kind of flat that you have to spend tens of thousands of dollars for with a real telescope. The Canon superteles are used very often for astrophotography. There are even ultra sensitive, ultra high speed imaging arrays that use dozens of Canon EF 400mm f/2.8 L II lenses with FLI cameras to image some of the faintest stuff in the universe. 


Canon L-series superteles make excellent telescopes. I don't know about other teles or superteles, but Canon's L-series superteles are extremely good.



weixing said:


> Anyway, I saw my friend's 130mm f6 StarFire and it's super sharp right to the edge, but the waiting list is 7 to 10 years...
> 
> Have a nice day.




The StarFire is an Astro-Physics scope. Astro-Physics makes excellent quality products, however they are pretty costly. From what I understand, AP is no longer making that particular scope...they stopped making it years ago (maybe even over a decade ago), so there isn't a waiting list, they simply aren't available unless you buy them used (and owners don't generally sell them). There is a newer 130mm f/6.3 StarFire that is currently in production, however it doesn't take years to get them...if it did, no one would even bother, that would just be ludicrous.


AP mounts are some of the best in the world, and in such demand and built literally with hand-made quality, that their order-to-delivery lead time is around eight months right now. (I.e. if you order an AP mount today, it wouldn't even start being manufactured and assembled until about six months out or so, and wouldn't be shipped until at least eight months out.) I figure the StarFires have a similar lead time, but I don't know of anyone who has had to wait over a year for any AP product lately. They just don't mass-manufacture, they don't even start manufacturing until they get an order, and it is truly hand-made quality (assembly is all done by hand, each and every product made is manually tested for quality and optimized for best performance, especially for mounts with absolute encoding, etc.) It's the price you pay to get high end, high quality astronomy and astrophotography equipment. It is not easy or quick to ramp up new people with the skill level required to deliver that kind of quality (although from what I have heard, companies like Astro-Physics are training new people to improve their turnaround.)


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## jrista (Oct 28, 2014)

kkelis said:


> That sunspot is HUGE!!! it must be 10 times the size of the Earth. Is that with the 600mm?




Yeah, gargantuan. It was an X-class flare level spot. They were expecting a LOT of energy from it, but I think it was pointed away from earth when flares occurred.


It was indeed shot with the 600mm. I should have tried imaging with the 2x TC...but for some reason I didn't think to try until the eclipse was over.




kkelis said:


> Here is mine from last year solar eclipse.
> 
> 3/11/2013 15:54
> 
> ...




Very nice. It's pretty amazing how much a 10-stop ND can do for imaging the sun.


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## jrista (Oct 28, 2014)

yorgasor said:


> I botched my eclipse photos. It was right at sunset on the east coast, I had to drive around a bit before I finally found a place with a low enough view to see the sun during the eclipse, and even then I just had a couple minutes to try and dial things in. I should've planned ahead a little better, and I should've experimented with my equipment ahead of time. Anyway, I got so frustrated with my results, I went out the next day to see what kind of sun shots I could get when I wasn't rushed.




Sorry you missed the eclipse. Image looks nice, though...that one cluster of sunspots is just giant.


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## jrista (Nov 3, 2014)

The Double Cluster


Two open clusters, in Perseus just near the border with Cassiopeia. About 1 hour integration, 100s subs, 5D III (full frame, and cropped and rotated framing.)


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## jrista (Nov 10, 2014)

I reprocessed my Pleiades image from a while back. I'd been waiting for clear skies to get more subs, I need about 260 to get the total integration time/SNR that I need to really take it to the limits without a lot of noise. Since I haven't had clear skies for a while, I decided to see what I could do with what I had.







I think this one definitely looks better than the last version, more detailed/colorful, and the faint outer IFN detail has better contrast.


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## Omni Images (Nov 10, 2014)

Well gentlemen, I am excited to be able to join you soon with posting some images.
I have been keeping my eye on things somewhat and have never been able to afford the tracking gear needed to do keep things in the veiwfinder without creating star trails for any longer than what ? 25 sec at 14mm at F2.8 with a huge iso setting ....
I found an entry level item which I am excited to start using the moment we get some clear skies
http://www.bintel.com.au/Mounts---Tripods/SkyWatcher-Star-Adventurer/SkyWatcher-Star-Adventurer-Bundle/1904/productview.aspx
I also just downloaded DSS .. so now all I have to do is work out how to use it all.
I am in the southern hemisphere and finding our polar axis is a little harder.


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## niteclicks (Nov 13, 2014)

[quote 
I think this one definitely looks better than the last version, more detailed/colorful, and the faint outer IFN detail has better contrast.
[/quote]

As much as I liked the last one, you did get even more out of this one. The wider fields is exactly why I bought the 5DIII. I was hoping this new moon would be good weather, but doesn't look like it. Last time out I had a terrible time with tracking and could only get about two minutes without trailing, found the polar scope badly out of alignment so fixed that . Here is Andromeda from that night, it needed a lot more exposure .

http://src3rsteve.zenfolio.com/p289498573/e11012ef6


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## jrista (Dec 27, 2014)

Bad weather has basically shut me down lately. Decided to start spending my clear nights at a dark site, as it's vastly more efficient to gather photons without LP than with. Here is my latest:








Orion's Sword - Wide Field with additional Dust and Reflections


Canon 5D Mark III
Canon EF 600mm f/4 L II
Orion Atlas EQ-G (Belt Modded)


Acquisition with BackyardEOS, processing with PixInsight and Photoshop. Total of 2h 20m integration for the background, grand total of ~4h total image data for bringing out the core (manual blending, this target has MASSIVE dynamic range.)


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## meywd (Dec 27, 2014)

Amazing job Jon, really beautiful, and so much detail in the dust, what are the light sources with cones of darkness on each side?

Another thing, when i see it full size, i see lots of noise in the dark areas, i expect a lot of noise since its a high ISO composite of many hours of long exposure, but this much color noise! is it a by-product of the Sensor, long exposure, composite, or all together? and shouldn't it be handled by dark frame subtraction? 

Thanks for sharing and sorry for the noob questions


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## jrista (Dec 28, 2014)

Thanks.  


So, there is noise. Lots of noise. It's only 2 hours of integration, and I probably need a minimum of 5 to really do it justice. It's just not easy to get that data, since there are only a handful of dark nights a month, and Orion is really racing towards the western horizon. I hope to gather another three hours at some point, which should help. 


The 5D III, as I've tried saying so many times on these forums, is one craptastically noisy sensor! It is NOT, buy today's standards, a low noise sensor, at all. Which is a little sad, for a camera barely three years old. That's where the color noise comes from.


As for electronic noise overall, it's actually fairly low. I used ISO 1600 specifically to get read noise low. Its around 3.x e-. I was also imaging at around 3C (it's the heart of winter here, nights are 15-18F), so the dark current is very low. The reason the darker regions look noisy is they have been very significantly stretched. I had 21.3mg/sq" skies where I imaged this, which is getting pretty close to the darkest possible 22mg/sq" skies on earth. That was necessary to even get a reasonable amount of photons on those dark areas. Still, on a per-sub basis, the darker areas probably only had maybe 5-8 photons/pixel/minute tops! 


So, yeah...there is noise. There is always noise, and when you do a ludicrous stretch like I did, that noise can present a bit of a problem. The only solution is to expose long enough to swamp read noise, and integrate more and more. I need three and a half more hours of integration for my minimum, and I would really prefer another 7 hours. 


Regarding dark subtraction, you have to match the dark frame temps to the light frame temps. That can be a major PITA, so I stopped bothering and now use dithering instead. Along with Winsorized Sigma Clipping integration, that takes care of the hot and cold pixels, sat tracks, etc. I still use biases and flats, though...and flats actually tend to increase noise a bit as it removes LP and vignetting.


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## Click (Dec 28, 2014)

Awesome shot Jon. Well done.


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## Click (Dec 28, 2014)

Jon, I have a question for you.

What are those triangles on both sides of some of the stars?


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## dcm (Dec 28, 2014)

Click said:


> Jon, I have a question for you.
> 
> What are those triangles on both sides of some of the stars?



Interesting, they seem to be concentric with the center of the image


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## meywd (Dec 28, 2014)

jrista said:


> Thanks.
> 
> 
> So, there is noise. Lots of noise. It's only 2 hours of integration, and I probably need a minimum of 5 to really do it justice. It's just not easy to get that data, since there are only a handful of dark nights a month, and Orion is really racing towards the western horizon. I hope to gather another three hours at some point, which should help.
> ...



Thank you for the answers, well i agree with you, but as you said you are stretching the data beyond what anyone would do in other types of photography, maybe ask Canon for an astro camera? but yeah i want a better sensor as well, though currently i am very happy with the jump to FF


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## meywd (Dec 28, 2014)

dcm said:


> Click said:
> 
> 
> > Jon, I have a question for you.
> ...



yeah these....stars?


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## Click (Dec 28, 2014)

I don't know if we can call them stars... but those luminous things.


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## jrista (Dec 28, 2014)

It's some kind of diffraction effect caused by the lens. Those are indeed stars. I'm not sure what causes it, but it's always been that way. I've noticed recently that my stars are not flat across the field, which has me worried that my lens has a decentered or tilted element. Frustrating, as if that's the case, it's probably going to cost me a fortune to get it fixed...and I don't know when or how it happened. 


Anyway, here is an updated version:













http://jonrista.com/2014/12/28/orions-sword-wide-field-dust-and-reflections/


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## jrista (Dec 28, 2014)

meywd said:


> Thank you for the answers, well i agree with you, but as you said you are stretching the data beyond what anyone would do in other types of photography, maybe ask Canon for an astro camera? but yeah i want a better sensor as well, though currently i am very happy with the jump to FF




Eh, no point in asking Canon for an astro camera. They are the only DSLR manufacturer that has produced any, the 20Da and the 60Da. They don't filter out as much red, so they pass a lot more hydrogen alpha emissions (the primary reddish/pink emission of hydrogen gas nebula.) The problem with DSLRs is they have rather non-linear data. There is always some kind of in-camera processing. Canon used to be more linear than all the alternatives in the past, but they have been doing more processing in-camera lately, particularly with the 7D II (and DIGIC 6). 


DSLRs make ok stop-gap astro imagers, but for anyone who is as serious as I am, the only real option is a CCD. CCDs have excellent data linearity and for the better manufacturers (i.e. QSI, FLI) they have perfect gaussian read noise (no banding, very few if any hot pixels), which is vastly superior for astro. The other benefit of a CCD is you can get them monochrome, and use various filters like LRGB (luminance + RGB) or narrow band (Ha, SII, OIII, NII, Hb, and a variety of other bands). The mono sensors have a far higher fill factor, no color noise to speak of, and are overall much more sensitive regardless of the filter used (simply because your using all of the sensors pixels for all bands.) 


I'll probably be getting a QSI 683WSG-8 soonish here. It's an APS-C sized sensor, the KAF-8300, full mono, with an 8-position filter wheel (LRGB, Ha, SII, OIII and unfiltered), off axis guider port, and has a perfect gaussian read noise distribution. It's a very expensive camera though (with the filters and the various necessary adapters for use with my Canon lenses and standard telescope equipment)...about five grand. So I won't be buying any other cameras any time soon...least of all Canon, Canon sensors, even their newest ones, are just too darn noisy with poor noise characteristics.


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## Click (Dec 28, 2014)

Thanks for your response, Jon.

Sorry to hear about your lens.


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## meywd (Dec 29, 2014)

Thank you very much Jon and sorry to hear about the lens, The local astro club guys told me the same regarding CCDs, but yeah its expensive, i have no doubt you will put it to good use, btw i like the updated one more.


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## niteclicks (Dec 30, 2014)

Very nice. I am always amazed at the clarity of you images. I find it hard enough to get any clear nights with light pollution I can't imagine needing 2 or 3 times as many without . Orion is in the perfect location for me right now, but we only have had one clear night in the last month and that was Christmas eve.


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## jrista (Dec 30, 2014)

niteclicks said:


> Very nice. I am always amazed at the clarity of you images. I find it hard enough to get any clear nights with light pollution I can't imagine needing 2 or 3 times as many without . Orion is in the perfect location for me right now, but we only have had one clear night in the last month and that was Christmas eve.




You need many times more clear nights imaging the same target WITH light pollution. You can get away with imaging for much less time WITHOUT light pollution. 


Why? Because LP is additive to the object signal. If I'm imaging from my back yard, red zone light pollution, for every single object photon I get from a nebula, I get anywhere from 10 to 100 photons from light pollution (depends on transparency). To get 10 object photons, I have to collect 1000 light pollution photons. For 20 object photons, I've collected 2000 light pollution photons. Light pollution is something we ultimately subtract from our images...we correct a bit of it with flats, then we offset the rest. That leaves behind whatever object signal that was collected. If I offset by 2000, my object signal would still be 20. That is VERY low.

So, if my goal is to expose to about 1500-2000 e- at ISO 800, with a gain of say 0.6e-/ADU, then my image level in 16-bit integer would be something like 2000-3333 ADU. After correcting with flats and offsetting for the light pollution level, I end up with an object signal of 15-33. I could expose for longer, but because LP is compounding in the signal so much faster than the object, even if I doubled my exposure again, 4000 photons or 6666 ADU, my object signal is still only 66 ADU. Problem is, at ISO 800, 4000 e- is already getting close to the saturation point of an APS-C sensor, and is likely over half the saturation point of an FF sensor. That's too much exposure, your stars are guaranteed to be heavily clipped. Light pollution thus limits your object exposure depth by making your images "skyfog limited" very quickly. 

Now, contrast this with a dark site. For every object photon gathered, I might gather 0.5 or 0.3 photons for skyfog (from light pollution, or at a truly dark site with 21.5mg/sq" or darker, from airglow). Then for every 2 or 3 object photons I gather, I get one skyfog photon. I can expose for much longer, or maybe just expose at a higher ISO for a similar amount of time (not generally recommended unless your imaging something REALLY dim, like the dust in my Orion Sword image.) For 100 object photons, I'd have 33-50 skyfog photons. Maybe even less (if airglow limited, you might expect about 0.1 skyfog photons for each object photon, meaning you can expose your object signal ten times stronger than skyfog.) Therefor, at a dark site, you are freed to expose for much longer, potentially as long as you want, before you become "skyfog limited"...which may be 10 to 1000 times longer or more than when imaging under light polluted skies. 

If your goal is to expose to 2000e-, in a backyard with a ratio of 100:1 skyfog vs. a dark site with a ratio of 1:5 skyfog, you would have to expose 80 times longer in your backyard to gather the same number of object photons as you would at a dark site. Your gathering 20 photons per sub in the backyard, but 1600 photons per sub at the dark site. So, 1600/20, or 80x. If your goal is to expose 5 hours worth of total object integration at ~1600 photons per pixel per sub, your subs are 4 minutes (240 seconds) long, then your gathering 6-7 object photons per pixel per second at a dark site. You'll gather a total of 120,600 photons per pixel over five hours. Conversely, to get the same number of object photons from your back yard, you would be gathering 0.083 photons per pixel per second. To gather the same 120,600 photons...you would need to image for a whopping 403 hours under light polluted skies!!! Assuming you take the same 240 second subs, your still gathering 2000e-, however most of that signal is skyfog. So you would need over 6050 subs to get the same signal from your backyard as at a dark site. 

Given that, on average, there are only 7 hours of total dark each night (a little more during winter, a little less during summer), it would take you 58 days to gather enough subs from a light polluted site. Assuming you started imaging an object as soon as it started rising high enough over horizon haze in the east, and continued until it was finally setting into the horizon haze in the west, you MIGHT have enough time in a single season to get enough subs to produce the same kind of signal from a light polluted yard as at a dark site. ;P (And, note, in reality, most places have a handful of clear nights a month to image, between cloudcover and the moon, so in a three-four month period of time you MIGHT get 15-20 clear nights tops...to get 6000+ subs on a single target, you would actually need YEARS to get all 57 full nights worth of imaging done.)

If your really interested in astrophotography, I highly recommend finding a close dark site. You might be surprised to find that, pointing either east or west, you have one closer than you think. There are a lot of light pollution maps on the web, but most are based on the bortle scale, which is a tool for visually gauging how dark your skies are, which involves how well you can see city light bubbles on the horizons. A "true or exceptionally dark" site on the bortle scale requires that LP bubbles NOT be visible on the horizons. That isn't necessarily required for imaging, you can often find skies with an SQM reading (sky quality) of >21 within 30-60 minutes from the middle of a downtown city area. Just image in the part of the sky that is dark, and in a few hours you might be able to gather enough "dark site" data that would be comparable to imaging for months from a back yard. You can use this site, which measures direct light levels from overhead, to find potential sites that might be dark enough to image from (anything blue or darker is good enough):


http://www.lightpollutionmap.info/#zoom=4&lat=4838950.03614&lon=-9735847.10785&layers=0BTFFFTT

The other option is to use a monochrome camera and narrow band (NB) filtration. Mono NB imaging blocks out 99% or more of the light, passing only very narrow bands of emission. You can image under LP, even when the moon is half or larger. The kicker here is you need a mono camera with a filter wheel and nice, very narrow band filters. A decent mono CCD is going to cost a couple grand, a filter wheel another grand, and the filters themselves could be anywhere from $400 to $1200 a piece. Expensive...but, if you don't have the ability to drive to a dark site all the time, it is the best alternative. Atik has some decent cameras and a nice filter wheel for pretty good prices, and Baader has some narrow band filters (little wider bands, but still narrow enough to be useful) for good prices. You might be able to get away with a mono CCD camera setup for about $3500 or so.


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## jrista (Jan 1, 2015)

Here is another one. My last image of 2014. Same equipment, same dark site, as the Orion's Sword image:








Managed to capture a number of galaxies in this one as well, maybe around a dozen or so. I highlighted the largest here:


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## Click (Jan 1, 2015)

Amazing shot Jon. Really beautiful. It's always a pleasure to look at your pictures. 

Happy New Year.


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## Flyingskiguy (Jan 1, 2015)

Wow jrista, those shots are incredible. Unbelievable detail. 

I've been making a few attempts at astrophotography lately. Unfortunately I live in a "white" zone for light pollution (right next to a large city). Here is a shot of Orion I took a few days ago. The cumulative exposure time was about 20 minutes, and was stacked in Deep Sky Stacker from forty 30sec exposures. No darks, flats, or bias frames. Taken with a 7D Mark II and EF 100-400L II. 

To be honest I am very happy with the result, considering the light pollution in my area. Aside from shooting from darker locations, do you have any recommendations for improving the image, or dealing with light pollution in general? Will simply increasing the number of shots help?


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## gruhl28 (Jan 1, 2015)

Hi Jon,

Just now looking back through this thread, nice work! I have one question for you. You have really nice red in the North American and Pelican nebulas and in some of the stars in the double cluster. I think I read that you're using Deep Sky Stacker to stack images, is that right? I took a few one minute subs of the double cluster a few nights ago with a 70D, and the individual frames show red stars but when I stack in DSS the red mostly disappears, and I can't seem to get it back when processing in Photoshop. I have had similar problems with the North American and Pelican nebulas. I know that the 70D cuts out a lot of the H alpha, but as I said I'm losing red in stars between the individual frames and the stacked result, so that can't be the explanation. And even with an unmodded 5D you're getting good red in the nebulas. What settings are you using in DSS (if you're still using DSS).
Thanks,
Glenn


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## 20Dave (Jan 1, 2015)

jrista said:


> I'll probably be getting a QSI 683WSG-8 soonish here. It's an APS-C sized sensor, the KAF-8300, full mono, with an 8-position filter wheel (LRGB, Ha, SII, OIII and unfiltered), off axis guider port, and has a perfect gaussian read noise distribution. It's a very expensive camera though (with the filters and the various necessary adapters for use with my Canon lenses and standard telescope equipment)...about five grand. So I won't be buying any other cameras any time soon...least of all Canon, Canon sensors, even their newest ones, are just too darn noisy with poor noise characteristics.



I purchased the 583WSG with the 5 position filter wheel a couple of years ago. The QSI cameras are incredibly well made - there was a lot of nice design work that went in, unlike some other CCD cameras that feel like the mechanical design was an afterthought. I wish that the 8-filter wheel was available when I purchased mine, but I'm interested mostly in galaxies anyway, so the 5-filter wheel is fine for now. I purchased it when I had the funds but little time, so I've used it much less than I would have hoped. But I'm planning on building a ROR observatory in the spring and now have more time to dedicate to this hobby, so I hope to start getting my money's worth out of the camera at long last.

I did a little AP using the 20D before I got the QSI camera. Not having to combine the LRGB data was convenient, but there is really no comparison between the DSLR images and the CCD images.

And FWIW, I just tried the free PixInsight demo with my most recent image. It is really difficult to get my head around it, but the results are better than I could get with Nebulosity + Photoshop. But, I am a novice at it either way.

Dave


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## dcm (Jan 1, 2015)

jrista said:


> Here is another one. My last image of 2014. Same equipment, same dark site, as the Orion's Sword image:
> 
> 
> 
> ...



No artifacts in the stars this time. Lens okay?


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## jrista (Jan 1, 2015)

Flyingskiguy said:


> Wow jrista, those shots are incredible. Unbelievable detail.
> 
> I've been making a few attempts at astrophotography lately. Unfortunately I live in a "white" zone for light pollution (right next to a large city). Here is a shot of Orion I took a few days ago. The cumulative exposure time was about 20 minutes, and was stacked in Deep Sky Stacker from forty 30sec exposures. No darks, flats, or bias frames. Taken with a 7D Mark II and EF 100-400L II.
> 
> To be honest I am very happy with the result, considering the light pollution in my area. Aside from shooting from darker locations, do you have any recommendations for improving the image, or dealing with light pollution in general? Will simply increasing the number of shots help?




Very nice! For heavily light polluted skies, without any LP filter, and without any calibration at all, that is VERY well done! Once you calibrate with bias, darks, and flats, you should be able to get a lot more detail out of that.


As for improving your images. You have two options. Find a dark site that's close enough to get to on a regular basis, or invest in an LP filter. If you are using an APS-C, you could get either the Astronomik CLS clip-in or the IDAS clip-in. If you are using an FF, then I do NOT recommend getting the Astronomik CLS-XL clip-in for Canon FF dslrs...the design of that filter is flawed, and it causes more problems than it's worth. You should get the IDAS LPS-V4 screw-on filter instead, which can be threaded 48mm for use with standard 2" T-adapters that attach DSLRs to telescopes, or if you are using one of Canon's great white lenses, you can get it in 52mm threaded for use with the drop in filter holder.


Personally, I say find a dark site. Use this map to find one:


http://www.lightpollutionmap.info/#zoom=4&lat=6156149.93155&lon=-11229480.6837&layers=0BTFFFTT


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## jrista (Jan 1, 2015)

gruhl28 said:


> Hi Jon,
> 
> Just now looking back through this thread, nice work! I have one question for you. You have really nice red in the North American and Pelican nebulas and in some of the stars in the double cluster. I think I read that you're using Deep Sky Stacker to stack images, is that right? I took a few one minute subs of the double cluster a few nights ago with a 70D, and the individual frames show red stars but when I stack in DSS the red mostly disappears, and I can't seem to get it back when processing in Photoshop. I have had similar problems with the North American and Pelican nebulas. I know that the 70D cuts out a lot of the H alpha, but as I said I'm losing red in stars between the individual frames and the stacked result, so that can't be the explanation. And even with an unmodded 5D you're getting good red in the nebulas. What settings are you using in DSS (if you're still using DSS).
> Thanks,
> Glenn




I think you would be surprised how much Ha you can get with modern DSLRs. All of my cameras are UNmodded...look at the Ha I'm picking up.  I get a lot. Personally, I like the amount I get...any more, an I think the Horsehead image would have been overpowered by Ha, which would have hidden the very faint blue reflection that's all over the place. (I think I have more blue reflection in my image than any other image of Horsehead I've ever seen...which I'm pretty happy about. ) 


I used to use DSS to integrate. Now I use PixInsight. I've learned some things about Canon RAW files lately. I've NEVER liked how Lightroom demosaiced my CR2 files, not for years. It always results in pretty blotchy data, lots of red color noise, soft detail in the shadows, etc. DSS has always done the same. I've learned that LR/ACR, DSS, and a good number of other RAW editors use the AHD form of demosaicing, Adaptive Homogeneity-Directed demosaicing. I don't think AHD is ideal for Canon data. 


I recently trialed Capture One 8, an alternative RAW editor to LR. I had a 60 day trial, and throughout that time, I definitely felt as though it was doing a better job with Canon CR2 files. It resulted in a finer grained noise, much lower color noise characteristic, less blotching, etc. Overall, I was pretty impressed with COne 8, and if anyone is looking to maximize their daytime photography quality, you should look into it. I let my trial lapse, and I've stuck with LR for now...simply because COne is a very different program, and has a tenth the camera compatibility, not to mention the fact that it does not work seamlessly with PS. I'm hoping that someday soon, Adobe may switch to the algorithm COne 8 uses. 


Which brings me to PixInsight. PixInsight is an astrophotography editing tool, specially designed with tools to make the most out of ultra low SNR astro data. Unlike ACR/LR and most other RAW editors, it uses VNG (variable number of gradients) demosaicing. The VNG demosaicing of PI is very similar to the demosaicing of COne 8. I suspect they are both based on the same core VNG algorithm, with different tweaks to optimize results for their intended use case. Anyway, VNG results in VASTLY superior results from Canon CR2 files. I don't now why, but the noise is clean, usually an order of magnitude lower STDev, very low color noise, practically no color blotch. I use the PixInsight BatchPreprocessing script to calibrate and integrate my images now, as it just does a better job. Not just with the demosaicing either, it is far superior at star registration and rejecting out-of-sigma pixel data (hot pixels, aircraft/satellite/asteroid trails, etc.) 


Anyway...PixInsight is not free. If you can afford the couple hundred bucks or so for it, I say go for it. You'll want it anyway if you really get into astrophotography...it's an essential tool, and WELL worth the money. If you use the BPP script, you shouldn't have too many problems with getting good results.


If you want to stick with DSS for now, then my advice is, register, calibrate, integrate...then just save off the data to a 16-bit TIFF file. Do NOT apply adjustments (checkbox in the save dialog), and do all of your processing in Photoshop. DSS does not render the integrated data well, and your just seeing it's poor rendering. Search the web for video tutorials on how to stretch your integrations with Photoshop, and go from there.


Regarding getting the deep red. A lot of my images from summer suffered from wicked-high dark current noise. A lot of the red in those images is false...blotchy color noise from Canon's heavily red-weighted color read noise. There is some Ha data in my images (less now during winter, with temps that hover around 0°C and ultra low dark current), but not a ton. What Ha data I have, I attribute to the power of PixInsight in helping me bring out. You might be able to bring out Ha data with Photoshop, but if you really want to get the most out of your images, PixInsight is a very worthwhile investment. It's a perpetual license, so once you buy it, you get updates until the next major version (which, at the current rate, is probably not going to be for another five to ten years at least. )


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## jrista (Jan 1, 2015)

dcm said:


> No artifacts in the stars this time. Lens okay?




Oh, there are artifacts. I just stopped down to f/4.5, which creates the starburst diffraction effect, which hides the wedges. Look closely, though...and you can still see the wedge. My lens element is definitely tilted, which you can tell from the heavily elongated stars in the upper left (see the astrobin version.) 


I like the starburst effect, so I usually stop down to f/4.5. I just forgot to with the Orion Nebula image.


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## East Wind Photography (Jan 1, 2015)

Tested out the sky-watcher star adventurer last night. Worked rather well with my 7d2 and 300mm f2.8l II. However needed a larger counterweight from an old Orion p.o.s. Mount...about the only good thing to come from that.

Seemed to track unguided pretty accurately and was able to take 30 sixty second subs of lovejoy at ISO 1600 without any drift errors. The moon had more of an impact than the mount.

Today I attempted to mount my 5d3 and 600mm f4 to it but with both counterweights it was still a bit top heavy. However I was able to lock the clutch and it tracked without stalling the motor. Took about 15 seconds to stabilize so I will likely have to use a manual cardboard shutter for the subs. I'm sure this combo exceeds the useful weight limit but it will be worth trying once the moon gets out of the way.

I have a trip planned next year to the Midwest and have been looking for something to take that will not require an extra suitcase. The skywatcher is small enough And takes about as much space as a couple of dslrs , excluding the tripod which has to go anyway.

I stacked the subs but having some issues with my laptop so the final will have to wait until that get resolved.

Here is one sub which I edited on my iPad.


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## StudentOfLight (Jan 1, 2015)

What an awe-inspiring thread!


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## dcm (Jan 6, 2015)

Just saw the updated *Pillars of Creation* in the *Eagle Nebula* taken by the Hubble. It make me appreciate the work you guys do even more.


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## East Wind Photography (Jan 6, 2015)

Yeah What I see jrista do with a photo editor is amazing. I've been trying to tease out my stack of 30 taken of Comet Lovejoy and it turns to mush every time I try to tease out the detail. 

A single shot from the stack looks better than the stack. 

It's obviously an art itself.


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## jrista (Jan 7, 2015)

Nice comet, East Wind! I haven't had the opportunity to image that yet (weather :'(). 


How are you stacking? There are some specific techniques to stack the comet separate from the stars, stack the stars separate from the comet, then combine the two. DSS can actually do it for you, it's decent. PixInsight has comet stacking capabilities as well...more manual, more complex, but the results can be amazing.


I would download DSS (DeepSkyStacker, free) and try that first.


@dcm: Hubble stuff puts most ground-based astrophotographer's work to shame. Having no atmosphere to contend with is a HUGE bonus for Hubble...it can resolve an incredible amount of detail. Seeing is the bane of all earth-bound imagers, although with cameras like the A7s, which is so incredibly sensitive, we may be able to employ lucky imaging techniques to solve that problem within the next few years. Lucky imaging (high speed imaging, allowing you to take tens of thousands to hundreds of thousands of frames, then discard any that aren't near-perfect, integrating only the best ones), combined with adaptive/active optics, is how the new Thirty-meter and Forty-meter telescopes from ESO will resolve more detail than Hubble (by a lot.) There are some adaptive optics options for ground-based imagers...their effectiveness has never been fully verified...but combined with lucky imaging, ground-based imagers with 16-32" scopes could produce some amazing results, for sure.


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## East Wind Photography (Jan 7, 2015)

jrista said:


> Nice comet, East Wind! I haven't had the opportunity to image that yet (weather :'().
> 
> 
> How are you stacking? There are some specific techniques to stack the comet separate from the stars, stack the stars separate from the comet, then combine the two. DSS can actually do it for you, it's decent. PixInsight has comet stacking capabilities as well...more manual, more complex, but the results can be amazing.
> ...



Yeah I have been working with DSS. Got a nice stack. background is bright due to the moon that night. The issue is in processing using photoshop and trying to stretch the tail out of the background. When I get done with the editing it looks like about 8 shades of grey and I give up to try again another time. I'm certainly obviously missing something.


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## jrista (Jan 7, 2015)

East Wind Photography said:


> jrista said:
> 
> 
> > Nice comet, East Wind! I haven't had the opportunity to image that yet (weather :'( ).
> ...




You want me to give processing the data a try?


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## East Wind Photography (Jan 7, 2015)

I also picked up a used 52mm drop in gelatin filter holder for 69 bucks. Condition was too good so paid a bit of a premium. I'll toss the glass and insert my new filter. Best deals are finding one with a scratch or crack in the glass.  

I had been wanting to pick up a lumicon comet filter for a while to pull out the C2 lines whenever they may show up. Was able to get it for 25% off. Aside from that it seems to be very good in the OxIII range 98% transmission so maybe some hope there for other things.


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## East Wind Photography (Jan 7, 2015)

jrista said:


> East Wind Photography said:
> 
> 
> > jrista said:
> ...



Its a lot of data. need to figure out where to stash it for you. The TIFFs from DSS about about 236MB each.


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## jrista (Jan 7, 2015)

East Wind Photography said:



> jrista said:
> 
> 
> > East Wind Photography said:
> ...




How many files are you getting from DSS? If you use comet stacking, you should have just one...


DSS may not be saving the TIFF compressed, either. And, for best results, if you are saving TIFF, you probably just want to save it as 16-bit integer. I'd reintegrate and save to 16-bit TIFF, then open in PS, save it out again, and choose ZIP compression. That should reduce the file size.


I only need one integration, whichever one is best.


I also have support for FITS editing, and 32-bit FITS files are usually much better. I can load that into PixInsight. Either way, I still only need just one.


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## East Wind Photography (Jan 7, 2015)

jrista said:


> East Wind Photography said:
> 
> 
> > jrista said:
> ...



Yeah after stacking it's 236MB. I have a couple of different stacks. One without a filter, one with a deep sky filter, and a 3rd taken the day prior but I only have maybe 12 subs but it has less moon. Got started too late.

Is it possible to attach large files to CR messages?


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## East Wind Photography (Jan 7, 2015)

ok let me see what I can do. Too late tonight to start re-integrating. Will try tomorrow and see if I can get you something a bit more manageable.


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## jrista (Jan 7, 2015)

Dropbox, Microsoft OneDrive, Box, etc. Tons of free online space. Gigs of it. I use OneDrive myself (I can just drag and drop into my OneDrive area in Windows, and it automatically syncs to the cloud drive.)


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## East Wind Photography (Jan 8, 2015)

Jon I have a question. I've seen some references of using lens profile correction and aberration correction prior to stacking. Does DSS read DPP or ACR sidecar files? I got to thinking about that and didn't see how that might work if we were using CR2 files as subs and not JPG. Any insight there?

I think I discovered where I was going wrong on the editing. My display adapter was not set up optimally and therefore my visual representation was being crippled. Never noticed it before but never had to stretch something as severe as this. Will give it another try tonight.


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## jrista (Jan 8, 2015)

Most of the references to lens profile correction are done in-camera. For example, Roger Clark uses the built-in camera dark subtraction and lens corrections to avoid having to calibrate his subs. That is effective, to a degree. It does not produce the best results. In-camera processing power is limited, so the algorithms are lower precision. In-camera processing isn't going to use the more advanced algorithms we have today to optimally calibrate your light frames either. Plus, single-frame dark subtraction can fix hot pixels, but it tends to increase random noise.


I still recommend generating and using a proper flat, and either dithering or using a proper master dark, for calibration. None of the astro integration tools support lens profiles or anything like that. So if you didn't take the frames with in-camera calibration on, then you can't do it after the fact.


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## East Wind Photography (Jan 8, 2015)

jrista said:


> Most of the references to lens profile correction are done in-camera. For example, Roger Clark uses the built-in camera dark subtraction and lens corrections to avoid having to calibrate his subs. That is effective, to a degree. It does not produce the best results. In-camera processing power is limited, so the algorithms are lower precision. In-camera processing isn't going to use the more advanced algorithms we have today to optimally calibrate your light frames either. Plus, single-frame dark subtraction can fix hot pixels, but it tends to increase random noise.
> 
> 
> I still recommend generating and using a proper flat, and either dithering or using a proper master dark, for calibration. None of the astro integration tools support lens profiles or anything like that. So if you didn't take the frames with in-camera calibration on, then you can't do it after the fact.



I thought the in camera lens correction was only applied to jpg. So you are saying it applies to RAW as well?


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## jrista (Jan 8, 2015)

I don't know if it applies to RAW or not. All I know is that's what Roger Clark uses, so maybe he stacks JPEGs. Regardless, in camera, or with ACR/LR, it is not the best way to go about correcting your field, not for astrophotography. It may be simple, but it is going to diminish the quality of your results. 


Generate and use a proper master bias, master dark, and master flat for the most precise results. To really get the best results possible, use PixInsight to do everything...calibrate, register, integrate, and process.


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## East Wind Photography (Jan 8, 2015)

So my stacks are coming out better. However I believe I possibly overexposed too much with the moon interfering. After I stack the tail gets lost more into the background. As if the stacking is also increasing the background glow. I used a stack of 6 from the day before and got a good tail but the noise is bad. 

Trying to get a stack of 30 Going now...but not sure of the moon glow.


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## jrista (Jan 8, 2015)

Stacking is increasing both read and photon shot noise:


TotalSNR = S/N = (S * n)/SQRT(n * (S + R^2))


If you are imaging under light polluted skies, then the light pollution is added into the signal:


TotalS = ObjS + SkyFogS


So, yes, the background sky is going to increase in level, and it is going to increase in noise. That's not a huge deal, you simply offset to bypass the skyfog. Problem is, that eliminates the part of the signal from light pollution, but it leaves behind the added photon shot noise that additional part of the signal introduced into the total signal. You tend to get more photons from light pollution than from the object in or near the city. So for any given pixel at 1/3rd histogram (the recommended exposure level when using a DSLR), you might have, on average, 100 photons from skyfog and 10 from your object. Your background sky IS going to be fairly bright. 


When processing, you can simply offset to reduce the background sky back to an acceptable level. That is easily done with the Levels tool in Photoshop. After stretching, you will have a lot of noise to contend with. You can either use more subs to solve that problem, or simply use more advanced noise reduction tools (PixInsight is packed with them), and get extremely skilled at using them.


Once you offset for skyfog, the tail should still stand out. You can use a more aggressive stretch to bring it out more, but again, that is going to reveal more noise. The best solution for that is to shoot at a dark site. See my previous answer about imaging with light pollution for the reasons why.


I can still give processing a try. I can figure out how to bring out the image details, and share my steps with you.


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## jrista (Jan 10, 2015)

*Comet Lovejoy C/2014 Q2*


I don't get to do comets often. They aren't in the sky that much, and even when they are, they are often low to the horizon during sunrise. Terry Lovejoy, comet-finder extraordinaire, discovered another comet in August 2014. It finally drifted into the northern horizon skies on December 24th, and I've been wanting to get some comet photons ever since. Finally got a chance last night:









In my haste to get some data before the moon came up, I ended up underexposing my subs. That resulted in the heavy banding of the 5D III showing through. I managed to eliminate most of it, but some is still visible in the coma. This was my first tracked comet image, and I managed to get some detail on the tail, which I'm fairly happy about. Hoping I get another opportunity to image this again, and get some better data.


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## East Wind Photography (Jan 10, 2015)

jrista said:


> *Comet Lovejoy C/2014 Q2*
> 
> 
> I don't get to do comets often. They aren't in the sky that much, and even when they are, they are often low to the horizon during sunrise. Terry Lovejoy, comet-finder extraordinaire, discovered another comet in August 2014. It finally drifted into the northern horizon skies on December 24th, and I've been wanting to get some comet photons ever since. Finally got a chance last night:
> ...



Really nice. And very nice you have dark skies! I'm going to try the 600 tonight but I'm not expecting much. What was your integration to get this?


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## East Wind Photography (Jan 10, 2015)

I see you even picked up a galaxy there on the right.


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## jrista (Jan 10, 2015)

East Wind Photography said:


> jrista said:
> 
> 
> > *Comet Lovejoy C/2014 Q2*
> ...




This was a really short integration. I had some connectivity problems, so I went with 30x30s ISO 1600 subs. I tried to get 50x45s ISO 800 subs...not sure if they turned out (that data is still on my laptop.) I actually got about 8 to ten galaxies in the frame, at full size.


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## East Wind Photography (Jan 11, 2015)

Just brutal...110 subs of lovejoy tonight with the 600 and 5d3. Didn't realize it was 18 degrees F outside. Good news is that the sensor stayed at 19C the entire time.

I ended up using ISO 1600 and 20 sec shots at f 5.6. Running them now to see how many have a decent score.

This will be the last op for a while as a front is coming in tomorrow. Next window will be Friday or Saturday night.


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## emag (Jan 11, 2015)

We had our ONE clear night, first in 3 weeks......and I had to go to NOLA that night. 4/5 days until the next possible night. New field flattener hasn't seen a single photon.


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## Mr Bean (Jan 11, 2015)

jrista said:


> *Comet Lovejoy C/2014 Q2*
> 
> 
> I don't get to do comets often. They aren't in the sky that much, and even when they are, they are often low to the horizon during sunrise. Terry Lovejoy, comet-finder extraordinaire, discovered another comet in August 2014. It finally drifted into the northern horizon skies on December 24th, and I've been wanting to get some comet photons ever since. Finally got a chance last night:
> ...


Nice one jrista


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## Mr Bean (Jan 11, 2015)

My attempt at comet Lovejoy, unguided.
5D3 with 300mm lens. ISO 25,000 1.3 seconds @ f4, uncropped


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## lol (Jan 11, 2015)

Here's my attempt of Lovejoy C/2014 Q2 last night. My Sigma 300 is lent out so I made do with a 150mm macro instead.

Equipment: Canon 7D2, ISO1600, Sigma 150mm f/2.8 macro at f/2.8, Astronomik CLS CCD filter, 161 x 30s exposures. Took more but rejected a load due to cloud. Tracking background stars unguided with lousy polar alignment.

Processing: Starting with PixInsight, flats, star align, comet align, stack, stretch, DBE (I messed up that order, should be done earlier), curves, photoshop.

Above is only the comet aligned stack. I've yet to do a star align stack.

I've tried to optimise viewing for the tail in this image. My local light pollution is rather rubbish.


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## weixing (Jan 11, 2015)

Hi,
Nice... I had no opportunity to took any image of it as it's raining season (rain or overcast) now, but luckily the sky clear up a bit yesterday night and had at least a visual look at the comet... 

Have a nice day.


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## gruhl28 (Jan 11, 2015)

Went out to image the Pleiades last night (haven't processed yet), took a couple quick shots of Lovejoy through the trees planning to come out after dinner when it was briefly out of the trees to take some better ones, but it was back in the trees by the time I finished dinner. Including a couple other recent images I've taken.

Jrista, belated thanks for your response to my questions a couple weeks ago re DSS and raw files. I've been trying to make due with Photoshop and the free DSS, but maybe I should give PixInsight a try.

Lovejoy and M31 taken with a 70-300mm on a Canon 70D at 300 mm f/5.6 (Lovejoy heavily cropped). NA nebula taken with 100 mm macro at f/2.8. M31 and NA nebula stacked and flats, darks, and dark flats calibrated with DSS.


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## East Wind Photography (Jan 11, 2015)

Pixinsight offers a 45 day trial version. I can't think of a better time to try it out and see if it helps. Though it may take 45 days just to learn how to use it.

Downside is in 45 days you have to cough up 230 euros!


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## jrista (Jan 11, 2015)

@lol: Very nice image! You got more tail structure than I did. One thing about imaging comets...they tend to spin, so the tails spin over rather short periods. You might actually get even sharper results by stacking fewer subs, since over the duration you imaged at, the tail was surely spinning (and thus, the relative motion would result in blur when stacked.) But very, very nice image! 


@Mr Bean, excellent image for a single frame! For sure!


@gruhl28: Great images! I'm glad you managed to get something going on the astro front. It's a fun hobby. Regarding PixInsight...it is a very different kind of program. My recommendation is, get the trial when you are certain you have the time to take advantage of it. There IS a learning curve. You might want to master some other things first before you dive into PI...however once you DO dive into PI, it without question has some of the most powerful tools available for astrophotographers.


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## East Wind Photography (Jan 11, 2015)

Seems that no matter what I do with DSS and the post in PS, this is the best I can get. By the time I work through the repetative curve process, the background ends up looking like 16 shades of grey. I know there is nice data here to be had but it's not coming out with the old school tools.

So I just submitted my trial license for pixinsight before I get too discouraged and give up.


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## jrista (Jan 11, 2015)

East Wind Photography said:


> Seems that no matter what I do with DSS and the post in PS, this is the best I can get. By the time I work through the repetative curve process, the background ends up looking like 16 shades of grey. I know there is nice data here to be had but it's not coming out with the old school tools.
> 
> So I just submitted my trial license for pixinsight before I get too discouraged and give up.




PixInsights calibration, registration, and integration tools are far better than DSS. The registration is far superior, and it includes a CometRegistration tool. I recommend following this:


http://harrysastroshed.com/pixinsight/pixinsight%20video%20files/2013%20pix%20vids/cometstack2/cometstack2.mp4


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## East Wind Photography (Jan 11, 2015)

jrista said:


> East Wind Photography said:
> 
> 
> > Seems that no matter what I do with DSS and the post in PS, this is the best I can get. By the time I work through the repetative curve process, the background ends up looking like 16 shades of grey. I know there is nice data here to be had but it's not coming out with the old school tools.
> ...



Good stuff. I'll be checking out likely all of their videos. Lol.

Today I have been experimenting with DSS settings and get varying results. They don't go into much detail on when some settings should be used or not...but I guess that's what you get for free.


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## East Wind Photography (Jan 12, 2015)

LOL. More DSS fail. Cant get a good stack using this software. Look at those artifacts!


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## jrista (Jan 12, 2015)

Yeah, I've been having a lot of problems with DSS comet stacking as well. I found a PDF recently that explained a specific imaging procedure. The guy was imaging with a mono CCD with color filters, so his sequencing was complex. The trick was to use 20-second gaps between frames to ensure that stars were fully separated from each other. That is the only way that DSS will be able to properly apply kappa sigma clipping to reject stars when it registers on the comet. Anything else, and you'll have problems. 


I've been integrating with PixInsight, and have had largely the same problem as with DSS. I think the star-gap technique is the right way to image a comet. If I get another change, I'll be employing it.


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## East Wind Photography (Jan 12, 2015)

jrista said:


> Yeah, I've been having a lot of problems with DSS comet stacking as well. I found a PDF recently that explained a specific imaging procedure. The guy was imaging with a mono CCD with color filters, so his sequencing was complex. The trick was to use 20-second gaps between frames to ensure that stars were fully separated from each other. That is the only way that DSS will be able to properly apply kappa sigma clipping to reject stars when it registers on the comet. Anything else, and you'll have problems.
> 
> 
> I've been integrating with PixInsight, and have had largely the same problem as with DSS. I think the star-gap technique is the right way to image a comet. If I get another change, I'll be employing it.



Ah interesting. Since I took 130x20sec subs, I can use every other one that passes a decent score and see how that works. That gives me a 21 second gap between subs. Surely I can get at least 40 subs still.


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## East Wind Photography (Jan 12, 2015)

East Wind Photography said:


> jrista said:
> 
> 
> > Yeah, I've been having a lot of problems with DSS comet stacking as well. I found a PDF recently that explained a specific imaging procedure. The guy was imaging with a mono CCD with color filters, so his sequencing was complex. The trick was to use 20-second gaps between frames to ensure that stars were fully separated from each other. That is the only way that DSS will be able to properly apply kappa sigma clipping to reject stars when it registers on the comet. Anything else, and you'll have problems.
> ...



So one of the issues I a see with pixinsight comet integration is that it assumes all subs are taken without moving the field of view. That is you specify where the comet is on the first and last subs and it interpolates the position on every other sub. I guess you have to do a star align on every sub first to normalize the fov then do comet integration.


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## jrista (Jan 12, 2015)

East Wind Photography said:


> East Wind Photography said:
> 
> 
> > jrista said:
> ...




Yes, generally that's how comet imaging works. Most things assume that (DSS does for it's default integration, where you only mark the comet in the first and last subs sorted by time index.) If you change the field between subs, then your on your own.


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## East Wind Photography (Jan 13, 2015)

jrista said:


> East Wind Photography said:
> 
> 
> > East Wind Photography said:
> ...



Wow. PixInsight with 8 subs and no calibration already has done better than DSS and photoshop. Need a few more days of learning before I have something to post.


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## East Wind Photography (Jan 17, 2015)

Here is comet Lovejoy from last weekend. I'm still learning pixinsight and that is much more daunting than actually taking the subs.

Working on some new subs I took last night. Good split in the tail. My biggest issues are finding any clear instructions on the finer settings within the tool. Experimentation seems to be the best way to learn.


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## niteclicks (Jan 19, 2015)

East Wind Photography said:


> Here is comet Lovejoy from last weekend. I'm still learning pixinsight and that is much more daunting than actually taking the subs.
> 
> Working on some new subs I took last night. Good split in the tail. My biggest issues are finding any clear instructions on the finer settings within the tool. Experimentation seems to be the best way to learn.



Looking good. I hear you on the experimenting, I am still trying to figure out how to best process what I have on the comet. I did manage to get some short subs For M42, but had to shut down before I had time to get any longer subs for the faint stuff. First clear night in months ( and I mean perfect ) and I have to get hit with a stomach bug ! Anyway, this is 133 x 14 sec taken on the 16th,a little over processed but at least I have something to work on.


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## Click (Jan 19, 2015)

Great shot, niteclicks. I am always impressed by the beautiful results that you get.


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## niteclicks (Jan 19, 2015)

Thanks, Click. I forgot to mention I took these with the SL1 as kind of a test. Those using one of the Vixen or similar trackers may find it a suitable option to shave some weight. I got mine during their refurbished sale last month and I like it so far, a few annoyances but usable.


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## East Wind Photography (Jan 19, 2015)

Here is Lovejoy last night. Clouds parted very late so no tracking. Iso6400 20x5 seconds, 100mm at f4. Light pollution was problematic. I stacked these in DSS then edited on my iPad. Was surprised to catch the reflection nebula in the Pleiades.


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## jrista (Jan 19, 2015)

Great images, guys! I'm glad to see some of you are getting into astrophotography.  It's a great hobby, especially if your an insomniac like me.  


nightclicks, excellent results with M42 there. You managed to pull out some of the faint outer dust, which is really quite a challenge. You must have some decently dark skies to do that.


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## niteclicks (Jan 19, 2015)

jrista said:


> Great images, guys! I'm glad to see some of you are getting into astrophotography.  It's a great hobby, especially if your an insomniac like me.
> 
> 
> nightclicks, excellent results with M42 there. You managed to pull out some of the faint outer dust, which is really quite a challenge. You must have some decently dark skies to do that.



Once I get out of the glow of Tulsa it's not to bad as long as the humidity doesn't swell the light dome.I can visually make out the milky way , but only because I know it's there ! Last Thrusday was probably the single best night in a year. Actually it was perfect, light to no wind, low humidity, excellent seeing and 40's to start. unfortunately I got sick before I got the longer subs for the faint stuff, and of coarse clouds have moved back in since. I think if I reprocess I can improve it some ( I have forgotten most of what little I used to know) , full size it is a bit over cooked the really faint stuff is really blotchy looking.


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## fish_shooter (Jan 19, 2015)

I see that I posted my Comet Lovejoy pic in the wrong sub-forum. It is a single exposure shot on a fixed mount tripod, nothing fancy - no equatorial mount, no image stacking. Just an 85mm f/1.4 lens @ 1.4 and ISO 3200 for 10 secs (so some earth spin is evident). Camera = 7D2 (pic already in 7D2 sub-forum). I can just barely detect a comet tail.


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## noncho (Jan 19, 2015)

Here are my tries with Lovejoy:

70D, Sigma 105 2.8 macro OS, 5 sec, 6400 ISO, freezing cold in the mountain







3.2 sec, 3200 ISO


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## East Wind Photography (Jan 20, 2015)

fish_shooter said:



> I see that I posted my Comet Lovejoy pic in the wrong sub-forum. It is a single exposure shot on a fixed mount tripod, nothing fancy - no equatorial mount, no image stacking. Just an 85mm f/1.4 lens @ 1.4 and ISO 3200 for 10 secs (so some earth spin is evident). Camera = 7D2 (pic already in 7D2 sub-forum). I can just barely detect a comet tail.



Nice shot. With this focal length and keeping the crop down you should be able to take it to 6400.


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## East Wind Photography (Jan 20, 2015)

jrista said:


> Great images, guys! I'm glad to see some of you are getting into astrophotography.  It's a great hobby, especially if your an insomniac like me.
> 
> 
> nightclicks, excellent results with M42 there. You managed to pull out some of the faint outer dust, which is really quite a challenge. You must have some decently dark skies to do that.



I used to do it the hard way back in the day. Started out with a cold camera. Used dry ice to chill the film down to about -20F then exposed for hours tracking manually with a joystick. I then upgraded to using hypersensitized film...soaking the film under temperature and pressure in nitrogen and hydrogen gas. Cost more but you could treat several rolls of film at a time. Stacking was something we did in the dark room by stacking multiple negatives in the enlarger and manually registering the stars. It was all painful and extremely time consuming. 

Digital has really improved things quite a bit for astrophotographers. You can achieve better results in far less time and effort once you learn the software side....and the best part is that can be done in the warmth of your living room.


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## TLau74 (Jan 20, 2015)

It's really amazing what you guys can do. I'm just starting to get into astrophotography. Here is my 2nd attempt at Orion Nebula. Shot with Canon 6D, 70-200mm F2.8L II (F2.8 @200mm), ISO 3200, approx. 200 images at 1.6s stacked with DSS. (Followed Forrest Tanaka's technique on YouTube.) I don't know if it is the settings I used or the technique I used for PP, it just doesn't look like I was able to get as much detail as some of you.


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## niteclicks (Jan 20, 2015)

TLau74 , careful this can lead to sleepless nights.  Looks a lot better than my first attempts at Orion, quite good for 1.6 sec. I think it is actually one of the harder objects due to its wide brightness range and the super bright core. Are you tracking? To get the fainter parts you need to expose the background if you can't see the background you can't see the stuff that is barely brighter than it( if that makes since?). Think of the last two screen adjustment bars on one of those gray scale screen adjustment bars and setting your screen up to see the difference in them . ETR works even better at night .


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## niteclicks (Jan 20, 2015)

Still a work in progress, really having a ruff time with this one. The tail is clear to me in the subs but getting it pulled out of the star field is really pushing MY limits. At least I had another hour of clear skies before the clouds moved in last night  This is with the 5DIII and 200 2.8l II, so it spans about 7.5 deg. here. I have some other processing steps to try and tons of subs, so maybe eventually.


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## TLau74 (Jan 20, 2015)

Thanks niteclicks. I'm not tracking automatically (if this is what you mean), only manually adjusting the lens position every 40 shots to get Orion more or less in the center of the frame allowing easier stacking in DSS. Each of the 200 shots taken is 1.6s each; so total exposure time is 320s or 5.3min. I'm already at 3200iso so I can either increase the iso to 6400 maybe still ok for the 6D (?) or I can double the number of subs taken (400 x 1.6s = 640s or approx. 10.7min total exposure). Which would be better, increase iso or # of subs? I want to use a similar technique to try to capture Comet Lovejoy. Friday should be another clear night and I want to take advantage of this (even though it will be around -5deg Celcius).


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## niteclicks (Jan 20, 2015)

You are doing a fantastic job doing it that way. At some point you hit a wall where noise swamps the signal and only longer exposures will help, Jrista could help you better. Maybe build yourself a barn door tracker . You already have good data on the brighter stuff, I would give it a try and add it to what you have.


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## East Wind Photography (Jan 21, 2015)

This was 12x50 sec at iso1600 with my 7d2 and 300mm f2.8 II lens at f4. No calibration. Stacked in DSS and then stretched with pixinsight.


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## niteclicks (Jan 21, 2015)

East Wind Photography said:


> This was 12x50 sec at iso1600 with my 7d2 and 300mm f2.8 II lens at f4. No calibration. Stacked in DSS and then stretched with pixinsight.



I like how you have processed it. What settings did you stack with ? Median should get rid of those satellite tracks .
Steve


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## East Wind Photography (Jan 21, 2015)

niteclicks said:


> East Wind Photography said:
> 
> 
> > This was 12x50 sec at iso1600 with my 7d2 and 300mm f2.8 II lens at f4. No calibration. Stacked in DSS and then stretched with pixinsight.
> ...



There is also one sub that did not register properly. The sequence was a test right after I got my star-watcher tracker. Was mainly interested in seeing how well it would track. The stacking was an afterthought after I discovered the images again. Once the skies clear up again I'll give it another run with some calibration frames.


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## niteclicks (Jan 21, 2015)

Looks like it tracked pretty well. What tripod did you use it on?


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## East Wind Photography (Jan 21, 2015)

niteclicks said:


> Looks like it tracked pretty well. What tripod did you use it on?



It's an induro carbon fiber that use with a wimberly mount ... Seems fairly stable with my 300. When I mount the 600 on the tracker its gets a bit wobbly but does ok as well as long as there is no wind.


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## niteclicks (Jan 21, 2015)

I guess I need to look at one in person. I have an old meade lxd75 that I could not get good tracking out of that I had intended to be portable mount. But at time I was using an 8" Newtonian that acted like a sail in the lightest breeze. I may dig it out and see how it behaves with a lens. I would love to have something easier to haul on trips.


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## East Wind Photography (Jan 22, 2015)

niteclicks said:


> I guess I need to look at one in person. I have an old meade lxd75 that I could not get good tracking out of that I had intended to be portable mount. But at time I was using an 8" Newtonian that acted like a sail in the lightest breeze. I may dig it out and see how it behaves with a lens. I would love to have something easier to haul on trips.



This is the reason I got the Astro-track astrophoto package. The unit is about the size of two Dslrs (excluding the tripod) and I can pack in my luggage with the tripod. It has an st4 interface as well so you can add a scope and guider to the setup for longer exposures. I've taken up to 60 seconds on it and it tracks well even along the ecliptic. Haven't had a need to go much more than that yet due to light pollution. However I am planning a 2 week trip to Yellowstone next year and I'm shaking out all of the new gear now so I Dont have issues once I get there. It seems to be the most portable option yet can easily handle the gear I intend to take with me. 300 2.8L ii, 5d3 and 7d2 Both with grips.

I think it's design capacity is 11kg.


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## Andy_Hodapp (Jan 27, 2015)

My third attempt at m42. Canon 5d mkii and Tamron 150-600mm at 600mm f/6.3, 1 second iso 6400, 115 light frames and ten dark frames. Stacked in DSS and edited in lightroom.



116 seconds by Andy Hodapp, on Flickr


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## jrista (Jan 29, 2015)

Great stuff, guys! Your really progressing! 


One piece of advice: Try to get longer exposures, rather than stacking tons of short exposures. Noise does average out, if it is the right kind of noise. Thing about read noise, it adds in a certain way, and it does NOT average out like dark current noise or photon shot noise. 


Here's the math (simplified a bit, it ignores other factors that I don't want to get into with you guys yet):


SNR = (n * S)/SQRT(n * (S + D + R^2))


n = sub count
S = signal
D = dark current
R = read noise


Notice here...R is SQUARED in the square root term. That basically makes it a constant. While everything else is scalar, R is squared, so it compounds as you combine more and more frames. It's the one kind of noise you have to watch out for, as if you combine lots of frames (115, for example) the read noise starts to add up, while all the rest of the noise averages out. The signal is combining as well, and the signal grows faster than the read noise, but read noise does not average out like everything else, so you have to be careful with it.


So, with the math out of the way, what does it mean? It means that getting the highest signal per sub is best. More specifically (and this involves more complicated math), you want to get your signal strength high enough in each sub that you totally swamp read noise with your "background sky". When you do that, you become photon shot noise limited, and read noise is effectively dealt with by a simple offset (i.e. when you stretch your data, you just shift the black point up, and that reduces the read noise contribution to zero.) Doing this with a DSLR doesn't actually require that you know the math...really, exposing long enough that the histogram for your images peaks at the 1/3rd mark (from the left-hand edge on most cameras and in all software, where the black point is) is generally enough to swamp read noise unless your combining more than a couple hundred frames. 


I therefor strongly encourage you guys to get the longest subs you possibly can, before you start getting elongated, eggy, or trailed stars. That generally means exposing for much longer than 1 second, and that requires some kind of tracking mount. But the difference is massive. Even if you go from one second to five or ten seconds (which, without a tracking mount, if you have large enough pixels and/or a short enough focal length, that could be possible), that would be a very significant difference in per-sub SNR, which would result in significantly better integrations.


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## jrista (Feb 2, 2015)

The D800/810 with black point hack has already proven to be a formiddable option for astrophotography. Seems soon Canon will not be the only company offering an astro-tuned DSLR:


http://nikonrumors.com/2015/02/01/rumors-new-special-nikon-d810-version-designed-for-deep-sky-astrophotography-with-increased-hydrogen-alfa-sensitivity.aspx/


Difference is Nikon would be offering the D810, a flagship model, in an astro-modded variant. I know a guy who does PHENOMENAL work with the D800:


http://www.astrobin.com/users/whwang/


My 5D III can't do that...at least, not with such little integration time. It's much noisier, even when imaging under extremely dark skies, with longer integration times. I'd need 10 hours minimum to get results that good. 


I wonder what Canon's 5Ds will be like. I truly hope Canon addresses their read noise issues...


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## East Wind Photography (Feb 10, 2015)

So I broke down and ordered a camranger. Mostly so I could use my ipad for micro focus in the field. Anyone else use a camranger for astrophotography and does it provide useful features?

I had been using a laptop for microfocus but I dreaded dragging that off to the midwest when I would have my tablet anyway.


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## jrista (Feb 10, 2015)

East Wind Photography said:


> So I broke down and ordered a camranger. Mostly so I could use my ipad for micro focus in the field. Anyone else use a camranger for astrophotography and does it provide useful features?
> 
> I had been using a laptop for microfocus but I dreaded dragging that off to the midwest when I would have my tablet anyway.




I know a bird photographer who uses one. He uses it to get difficult shots, like Kingfishers. I don't know of anyone who uses one for astro...but if it helps you focus, I say more power to you.


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## cazza132 (Feb 12, 2015)

Astronomy has been a interest of mine since I was 10 years old. Now, some 30 years later, an Astrotrac (tripod mounted star tracker (non-guided)), a DSLR and a few lenses have given me a chance of actually taking photos of the objects I saw in astronomy books, magazines, etc - and I am really stoked! Here's a few astro shots taken recently:

The Great Orion Nebula (M42 + M43 + Running Man)
Full spectrum modded 6D + 70-200 f2.8L II lens with x2 TC @ 400mm. Tracked using an Astrotrac.
4x120s, 8x60s, 4x20s, 4x8s and 4x3s at f5.6 on ISO3200. Dark frame subtraction on the 120s and 60s shots.
Aligned with PT Gui and processed with Fitswork.

Lagoon Nebula and the Trifid Nebula
Full spectrum modded 6D + 70-200 f2.8L II lens with x2 TC @ 400mm. Tracked using an Astrotrac.
4x120s, 4x30s, 4x8s at ISO800 + 10x120s at ISO3200. All at f5.6. Dark frame subtraction on the 120s shots.
Aligned with PT Gui and processed with Fitswork.

Eta Carina
Full spectrum modded Canon 6D, 200mm, ISO3200, 4x120s, 4x30s, 4x8s and 4x3s. AstroTrac. Hutech LPS-D1 lens mounted filter

Eta Carina - Wide field
Full spectrum modded Canon 6D, 200mm, ISO3200, 4x120s, 4x30s, 4x8s and 4x3s. AstroTrac. Astronomic CLS-CCD XL-Clip filter

Comet Lovejoy (C/2014 Q2)
Canon 6D
70-200 f2.8L II + 2x TC @ 400mm, f5.6
20x120s exposures at ISO3200
Astrotrac used for tracking the stars

Heart of the Milky Way Widefield
Mosaic using a Sigma 35mm @ f2.2 on a full spectrum Canon 6D. An Astronomic 'L' clip in filter was used. Astrotrac used for tracking.

Hope you enjoy.


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## jrista (Feb 12, 2015)

EXCELLENT images, Cazza! Your modded 6D sucks out far more Ha than my unmodded 5D III does...really amazing. I'm amazed these are all tracked using the AstroTrac...that little thing must handle the weight very well. 


Looks like you have access to more southerly skies. The Carina Nebula is something I can't see, but I find it fascinating. Love your wide field of the area, truly excellent. 


Your Lovejoy is superb as well! 


Welcome to the forums!


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## cazza132 (Feb 12, 2015)

jrista said:


> EXCELLENT images, Cazza! Your modded 6D sucks out far more Ha than my unmodded 5D III does...really amazing. I'm amazed these are all tracked using the AstroTrac...that little thing must handle the weight very well.
> 
> 
> Looks like you have access to more southerly skies. The Carina Nebula is something I can't see, but I find it fascinating. Love your wide field of the area, truly excellent.
> ...



Thanks jrista!

I live on the Sunshine Coast (about 26deg S) - just north of Brisbane, Australia - so I am lucky to have a full view of the many goodies in the southern sky.

Yes, the full spectrum modification does make a huge difference - like about 400%+ increase in Ha sensitivity. A visible+Ha band pass filter that cuts infrared is essential. The FS 6D is also very handy for daytime (and night time) IR work.

The Astrotrac does pretty well, but can be fiddly to get right. I usually spend about 45min drift aligning before shooting. And you have to keep the center of gravity of the camera and lens close to the center of rotation of the Astrotrac. If I'm lucky, on a good night, I can get 4min subs with a 400mm FL.

BTW - Excellent work on your website! Well done with your recent images of Andromeda, Pleiades, M42 and horsehead - standouts for me. All with an unmodded 5DIII?


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## jrista (Feb 12, 2015)

cazza132 said:


> jrista said:
> 
> 
> > EXCELLENT images, Cazza! Your modded 6D sucks out far more Ha than my unmodded 5D III does...really amazing. I'm amazed these are all tracked using the AstroTrac...that little thing must handle the weight very well.
> ...




Yeah, once you get rid of Canon's stock IR/UV cutoff filter, things improve dramatically for astro. I've resisted doing that with my 5D III, as I don't want to mess with it's existing IQ for my birds and wildlife, and am planning to get a mono CCD with filter wheel and narrow band filters soon here anyway.


The 5D III definitely struggles to get any Ha though.



cazza132 said:


> The Astrotrac does pretty well, but can be fiddly to get right. I usually spend about 45min drift aligning before shooting. And you have to keep the center of gravity of the camera and lens close to the center of rotation of the Astrotrac. If I'm lucky, on a good night, I can get 4min subs with a 400mm FL.




Thanks for the insights. It is possible to use PHD to do very rapid drift align. I am not sure if that would be possible on the astrotrac, PHD has compatibility with certain guide cameras and may not work with a DSLR. I can dial in a PA error of about 30 arcseconds or less in about 10 minutes or so using the technique I describe here, though:


http://www.cloudynights.com/topic/472874-drift-alignment-with-phd2-the-bookmark-technique/


If you can figure a way to make it work, it might get you dialed in much faster.


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## jrista (Feb 15, 2015)

Here is another. I just had a run of six clear nights...something I've never seen before...and got a ton of data on several targets. Most were galaxies, the one nebula was Rosette. This is an 11 hour integration (164x240s subs). 

*5D III + 600mm f/4 + 1.4x (840mm 1.55"/px) on Atlas mount*

Two versions, one "narrow band" like and one "natural color":













This is my longest integration to date, at 11 hours. I did this from my back yard with an IDAS LPS-P2 light pollution filter. That's replacing my Astronomik CLS filter, and it's actually quite amazing. Not entirely dark site quality data, but quite good data nevertheless.


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## Click (Feb 15, 2015)

Awesome series, cazza132. 8) Well done.


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## meywd (Feb 20, 2015)

Click said:


> Awesome series, cazza132. 8) Well done.



+1 Indeed amazing shots



jrista said:


> Here is another. I just had a run of six clear nights...something I've never seen before...and got a ton of data on several targets. Most were galaxies, the one nebula was Rosette. This is an 11 hour integration (164x240s subs).
> 
> *5D III + 600mm f/4 + 1.4x (840mm 1.55"/px) on Atlas mount*
> 
> ...



these are really beautiful, i like the second one most but both are superb, maybe you should move to a more sunny climate for more chances to get longer exposures, it seem that's your only real limitation


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## Mr Bean (Feb 21, 2015)

Wow, stunning images cazza132 and jrista.


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## Canon1 (Feb 21, 2015)

jrista said:


> Here is another. I just had a run of six clear nights...something I've never seen before...and got a ton of data on several targets. Most were galaxies, the one nebula was Rosette. This is an 11 hour integration (164x240s subs).
> 
> *5D III + 600mm f/4 + 1.4x (840mm 1.55"/px) on Atlas mount*
> 
> ...



John, 

Outstanding Details! This must look great at 1:1. One comment, on the second image the blue halos around the stars are a bit detracting. Cleaning those up, and a little color correction (less blue) in the stars would really strengthen that image. Im guessing these are left over from your Light Pollution Filter. Excellent work!


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## jrista (Feb 22, 2015)

Canon1 said:


> jrista said:
> 
> 
> > Here is another. I just had a run of six clear nights...something I've never seen before...and got a ton of data on several targets. Most were galaxies, the one nebula was Rosette. This is an 11 hour integration (164x240s subs).
> ...




Actually, the first image is more what I got strait out of camera. The IDAS LPS-P2 actually produces great stars with great color balance, but it doesn't handle the deeper pinks of emission nebula as well. The blue halos are due to the processing, which I am working on. I need to figure out how to properly reduce the stars in both the luminance and RGB images before combining them. I am also working on doing some pre-stretch masking on the stars in the second color version to prevent them from becoming overly blue (a more neutral white-based would be ideal.)


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## Schmave (Feb 26, 2015)

Wow, you guys are putting up some amazing shots. I really only started trying my hand at some astrophotography recently, and only using a 70D + 70-200 f/4, but here is my first attempt at the Orion Nebula:




Orion Nebula by Justin Kane, on Flickr

This is nowhere near what some of you guys are doing, but it is really the first deep sky object I have tried to image. I actually took this from the balcony at my house in northern San Diego. This was 87 1.0s, ISO 1600 subs with 48 dark frames and 21 bias frames with my lens @ 200mm f/4. I also tried using 1.6s exposures but was getting some motion blur and didn't think it looked as good. Even though it doesn't fill the frame it is really cool how DSS can clean up the image and show some of these objects. 

I am really starting to understand, though, that to step it up to the next level you NEED a tracker to increase your exposure times. I'm not sure if I'm ready to shell out for one though, lol. 

Attached is a 50% crop...it was looking kinda fuzzy at 100% crop.


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## jrista (Feb 27, 2015)

Nice work, Schmave.  Glad you gave it a try. I would be willing to bet, with a little bit more tolerance for some noise, that your data has more information in it than you think. It's a classic beginner "mistake" to try and make the background totally black. Thing is, space isn't black (very, very few areas of the sky actually have a black background, and none of the areas with emission nebula, which are all along the milky way, have a black background at all...there is tons of faint dust and filaments of emission nebula scattered all about the milky way.) 


I would work on keeping your background level above black...maybe 20-30 levels. You should be able to bring out more of the nebula then. You will have more noise, but noise is just a fact of life with astrophotography...we work with such weak signals.  Keep it up! You've just started a very long journey. The next step would be to get some kind of tracking mount...be it a Polari or AstroTrac, or something larger and more expensive, once you can track, you'll see your ability to get deeper exposures increase dramatically.


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## Schmave (Feb 27, 2015)

Thanks jrista! Maybe I'll go back and see if I can do some better processing on this data. I used Lightroom on the tif output from DSS. Do you see any limitations with Lightroom for this type of post processing? Would Photoshop be better? Do you know of any good tutorials for post processing in either Lightroom or Photoshop with the output tif from DSS? Thanks in advance.

I'd have to say, looking at the images you have produced is making me want to get into this a bit more. I'll have to work on convincing the wife about getting a tracker...


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## niteclicks (Feb 27, 2015)

Rodger Clark at clarkvision.com has some photoshop advise and alot of other astro related info, most above my paygrade but intresting. If you get serious or just have free funds the dedicated programs can really be worthwhile for getting every last drop from the data.


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## candc (Feb 28, 2015)

cazza132 said:


> Astronomy has been a interest of mine since I was 10 years old. Now, some 30 years later, an Astrotrac (tripod mounted star tracker (non-guided)), a DSLR and a few lenses have given me a chance of actually taking photos of the objects I saw in astronomy books, magazines, etc - and I am really stoked! Here's a few astro shots taken recently:
> 
> The Great Orion Nebula (M42 + M43 + Running Man)
> Full spectrum modded 6D + 70-200 f2.8L II lens with x2 TC @ 400mm. Tracked using an Astrotrac.
> ...



great images, jrista recommended that mount so that is what i am thinking of getting. they make what's called the "travel system" it seems to be everything i would need to get started except for a dovetail adaptor. 

judging from your images i would expect you also recommend it. 

would you suggest getting the whole "travel system" or just specific components?


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## East Wind Photography (Feb 28, 2015)

I prefer this tracking system for travel use.

http://www.bhphotovideo.com/c/product/1092106-REG/sky_watcher_s20510_star_adventurer_motorized_mount.html


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## candc (Feb 28, 2015)

East Wind Photography said:


> I prefer this tracking system for travel use.
> 
> http://www.bhphotovideo.com/c/product/1092106-REG/sky_watcher_s20510_star_adventurer_motorized_mount.html



thanks, seems like a good value.


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## East Wind Photography (Feb 28, 2015)

candc said:


> East Wind Photography said:
> 
> 
> > I prefer this tracking system for travel use.
> ...



Holds a lot of weight too. I can get my 600 F4L with my gripped 5D3 on it but need extra counter balance. But it works. With my 300mm F2.8L it's a perfect balance with only one counterweight. You would likely need the wedge and a couple of other things so if that seems like a good value, make sure you get everything you need.


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## jrista (Mar 1, 2015)

Schmave said:


> Thanks jrista! Maybe I'll go back and see if I can do some better processing on this data. I used Lightroom on the tif output from DSS. Do you see any limitations with Lightroom for this type of post processing? Would Photoshop be better? Do you know of any good tutorials for post processing in either Lightroom or Photoshop with the output tif from DSS? Thanks in advance.
> 
> I'd have to say, looking at the images you have produced is making me want to get into this a bit more. I'll have to work on convincing the wife about getting a tracker...




I wouldn't use Lightroom for processing. Photoshop is significantly better, and there are a number of actions packages out there that can make things easier (Look for Carboni's Astro Actions). 


Ultimately, Photoshop isn't even the most ideal tool for astro processing. It's great for beginners as many beginners already have it, but if you end up serious about the hobby, I highly recommend looking into PixInsight. It's a program designed specifically for astro image processing, including integration (the stuff DSS does, only PI is WAY better at it.) 




niteclicks said:


> Rodger Clark at clarkvision.com has some photoshop advise and alot of other astro related info, most above my paygrade but intresting. If you get serious or just have free funds the dedicated programs can really be worthwhile for getting every last drop from the data.




Roger Clark has some good baseline information, and some good basic tips. Clark does most of his imaging with pure DSLR equipment, and a lot of his recommendations, while aiming for simplicity, only work with pure Canon-branded DSLR equipment. He effectively bypasses image calibration by using camera features like LENR and lens calibration and very high ISOs to get decent images, without any real work. If that's in line with your own goals, Roger's method is great. 


That said, Roger's image processing is not top notch. His astro images often have artifacts, color balance issues, and other things, probably because of his "light touch." If you want to get better results, I recommend joining Cloudy Nights forums, find the Beginner and Intermediate Imaging forum, and start reading. That is probably the most helpful forum on the net for beginner astrophotographers, it's where I hang out myself (I'd call myself intermediate now, far expert or advanced...but I have enough knowledge to help true beginners get rolling.)


Once on the CN BII forum, you can start asking questions, and you'll quickly be directed to the best resources on the net for beginners, from making the hardware choices, to learning acquisition, to guiding, to processing.


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## jrista (Mar 1, 2015)

East Wind Photography said:


> candc said:
> 
> 
> > East Wind Photography said:
> ...




While you can barely fit a 600/4L and 5D III on the Star Adventurer, it is not recommended. The rule of thumb for imaging is to use only half the rated capacity. More than that, and your tracking accuracy will suffer, which will affect your stars. You shouldn't put more than 5-6 lb on the Star Adventurer for best results. You might get away with 7-8lb, but with longer lenses your star profiles will suffer (you'll have bloated stars, and you'll lose the benefits of the increased resolution of a large lens like the 600mm f/4). 


I use an Orion Atlas, a $1500 mount with a 40lb capacity, and at barely 20lb I am still not able to get ideal stars. I've reached the point in my imaging where instead of obsessing over things like just getting tracking working reliably at all, I am now obsessing over maximizing my mount's performance to get the tightest stars. I've come the the simple conclusion that a $1500 mount with 40lb capacity is simply not capable of giving me sub-arcsecond performance, even when guided, with a mere 20lb load. 


There are two levels of alternatives. There are the $5000 mounts, like the CGE Pro, the Orion HDX110, the Losmandy Titan. These can perform well, and have higher capacities, but they aren't engineered much better than the entry level mounts that run for $1500-$3000. They can get to 1-2" guided performance, but still can't get to the holy grail of true sub-arcsecond performance (where the worst case performance is still less than an arcsecond peak-to-peak (P2P) periodic error (PE).) Only the high end mounts, which start at $8000 for 45lb worth of imaging capacity, can give you tracking performance that averages >1" PE and 0.1" or better guided performance (which is necessary when you start imaging at a scale of 1"/px or larger...in my case, I am trying to image at 0.73"/px and simply can't do it with my mount.)


The 600/4 and 5D III is 2"/px image scale, and to get the best stars, you really want to keep your guided tracking at around 1-1.25" RMS. The 11lb capacity of the Star Adventurer is not going to give you that kind of performance, not even at half load, let alone full load. You might be able to get away with a 5D III and 300mm f/2.8 on that mount, but I think it would be difficult to get good performance out of it. The 5D III and 400mm f/5.6 would probably do much better.


For beginners, the best recommendation is to get the biggest mount you can possibly afford, and get a small, short, fast refracting telescope (or lens) as your first telescope. That maximizes the mount capacity (i.e. an Orion Sirius or Atlas), and minimizes load, thus maximizing your potential to get the most out of the equipment without a lot of hassle. Focal lengths ranging from 300mm to 600mm are generally recommended for beginners. Once your up over 800mm through 1200mm, your image scales drop to the point where mounts like the Sirius or Atlas are barely going to deliver what you need without extra work (i.e. most Atlas users who are imaging at 1200mm or longer have hypertuned and possibly belt modded their mounts...or, they skipped the Atlas and went strait to the Atlas Pro, which is basically hypertuned and belt modded right out of the box, for another $500 tacked onto the price.)


If your looking at something like the Astro Trac or Sky adventurer, you should be thinking much more wide field. Anything from ultra wide (14mm through 80mm), maybe 100-200mm. To give you guys and idea of how big these fields are (assuming a FF camera like the 5D III or 6D). The ultra wide focal lengths like 14-80mm are either "whole sky", "constellation", or "asterism" in terms of the field coverage. After that, up to 200mm or so, then you can start zeroing in on the really large regions of nebula, like the greater Cygnus region, or the entire Orion Belt+Sword complex, or both Heart and Soul nebulas in Cass, etc. At 600mm your down to just Orion's Sword or the end of his belt where Horsehead is, or just Heart or Soul nebula, or just California and Pelican nebulas in Cygnus, Andromeda Galaxy, etc. At 1000mm, your down to portions of nebula, small nebula (Wizard, Elephant Trunk, Crescent, Tulip, etc.), medium sized galaxies like Triangulum, and beyond that your into bulk (small) galaxy ultra high resolution nebula imaging. Much beyond 1200mm, and you have to start explicitly looking for scopes that have truly massive apertures, and much larger sensors with gargantuan pixels, just to get a reasonable image scale. It's not uncommon to find FF sized CCD sensors with 9 micron pixels being used at 1600-3000mm. A lot of the larger scopes support 65-70mm image circles, which cover 37x37mm and 49x37mm "large format" sensors that have 9, 12, and even 24 micron pixels.


So, as beginners, you should be thinking what is the shortest telephoto lens you can use, and what is the biggest mount you can possibly afford. Shortest Scope + Biggest Mount = Least Hassle, Most Fun. With an AstroTrac or Star Adventurer, I'd say 400mm f/5.6 or around there should be the limit. If you are willing to deal with some frustrations, you might be able to work a 300mm f/2.8 on a Star Adventurer, but just prepare yourself for dealing with tracking issues and other problems about half the time.


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## candc (Mar 1, 2015)

Hi Jon, 
Thanks for the advice. I am trying to look at something that is easy to setup and learn with, but would still be useful to hang onto even if you move up to bigger and more precise gear. From what I have seen and read the astrotrac looks good. It has a larger capacity than the comparable ones. I think I will get the wedge and tt320-ag. Use it on a rrs tvc-43 tripod. That should be good for doing wide field stuff for a beginner and more if you figure a little bit about what you are doing. I checked out some of the forum posts at cloudy nights, even the "beginner" section seems confusing. Its like starting to learn another language.


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## Omni Images (Mar 1, 2015)

Hi Guys, I bought myself the star adventurer a few months ago, but have hardly had a clear night since, plus I am in the southern hemisphere and it's not getting truly dark till about 10 pm, past my bed time .. ha.. well add a few hours of trying to get a few shots and it is.
I mostly wanted it for wide field shots. So I didn't have to push the iso up to like 3200 at F2.8 and about 25 to 30 sec exposures.
I was hoping it would allow me to drop the iso and stop down a little but and just extend the exposure time to still get the milky way come up nice and bright.
I recently bought a Phase One with the P45+ back that's a CCD sensor and high iso is not it's forte.
So yeah looking forward to winter here soon and longer nights.
BIG issue this side of the world is finding polar alignment, we don't have such a bright pole star as you guys, so I really need dark skies to even get close .. so far no luck in finding true polar south yet even ....
I do have the new 100-400 with a 1D4 so will give that a go also, but finding polar south is my first hurdle. It seems a bit fiddly and hard to view through that's all.
I hope I am on the right track anyway and can pull out some nice medium format milky way shots, I also want to include ground scenery in the shots, I know I'll get some horizon movement issues merging the two shots together, but hope it's not too much.


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## emag (Mar 1, 2015)

I've been looking up at the sky for 50+ years and pointing a camera at it, with and without telescopes, for most of those years. Never had extremely deep pockets, so I've learned to make do with what I can. I do most of my imaging with a CG5-ASGT mount to which I attach any one of several scopes / cameras. Due to light pollution in my area, I'm limited to subs of 30 – 90 seconds unless I travel to a dark site. Living at sea level, I also have frequent issues with seeing – deconvolution is a must when processing with PixInsight. I have no problem getting seeing-limited stars with a 2000mm telescope, although I often bring it down to ~1250mm with a focal reducer or use a 1000mm scope. An EQ6 class mount would be better, but it costs more than I'm willing to spend right now and wouldn't do anything for seeing. This image of Thor's Helmet is cropped from a stack taken with a 6D on an 8 inch f/5 Newtonian. My field computer was OOC that night, so these were 30 second subs, unguided.

http://www.pbase.com/emagowan/image/159120626 

For carrying a camera with a wide to medium telephoto lens, I adapted my old C8 drive base to hold a tripod head. Even that old spur gear drive is good for 30 second exposures. These old C8 scopes, with wedge and tripod, are often available for a great price on Astromart. If you can find one of these, a little bit of wood and a few hours work will get you a tracking camera mount that works quite well. 

http://www.pbase.com/emagowan/image/146520833

And an image of Orion with a modified 40D and an EF50/1.8, taken with that mount. That lens is somewhat atrocious unless stopped down to at least f/3.5. I have a old Takumar 50/2.0 and a Dandelion adapter, I've used it for day shots but now I'm curious to try it for astro.

http://www.pbase.com/emagowan/image/159209082 

NGC2467, taken with the 6D on the C8 with focal reducer, guided. A good but not great night, I was driving through fog on the way home.

http://www.pbase.com/emagowan/image/159276557


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## East Wind Photography (Mar 1, 2015)

Omni Images said:


> Hi Guys, I bought myself the star adventurer a few months ago, but have hardly had a clear night since, plus I am in the southern hemisphere and it's not getting truly dark till about 10 pm, past my bed time .. ha.. well add a few hours of trying to get a few shots and it is.
> I mostly wanted it for wide field shots. So I didn't have to push the iso up to like 3200 at F2.8 and about 25 to 30 sec exposures.
> I was hoping it would allow me to drop the iso and stop down a little but and just extend the exposure time to still get the milky way come up nice and bright.
> I recently bought a Phase One with the P45+ back that's a CCD sensor and high iso is not it's forte.
> ...



The star adventurer polar scope has the southern hemisphere polar star field built into the reticle. Provided you can see the polar stars you should be good to go. I think it would be much easier than northern polar alignment which requires us to have an app or a slide rule to figure it out.

You would just overlay the pattern in the polar scope and you are done.


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## East Wind Photography (Mar 1, 2015)

jrista said:


> East Wind Photography said:
> 
> 
> > candc said:
> ...



I agree that bigger is always better but the point is what are you going to travel with? Often times we have to make due with less. So while a 600mm on a star adventurer is not ideal, you can make due but have to shoot a lot of subs and weed out the bad ones. I could not see traveling with anything larger than the sky watcher astro package.


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## jrista (Mar 1, 2015)

East Wind Photography said:


> I agree that bigger is always better but the point is what are you going to travel with? Often times we have to make due with less. So while a 600mm on a star adventurer is not ideal, you can make due but have to shoot a lot of subs and weed out the bad ones. I could not see traveling with anything larger than the sky watcher astro package.




I've traveled with my Atlas to dark sites about a dozen or so times now. It isn't as portable as an AstroTrac or StarAdventurer, but it is still quite portable. I usually get it physically set up in about 10-15 minutes, including all connections to batteries and the laptop. 


The mount I am looking at now is the Astro-Physics Mach 1 GTO. It is a high end mount, $8000 new (less used, maybe by a grand or so), but it is actually even more portable than the Atlas, and has a true 45lb imaging capacity. The Mach1 breaks down into several parts, the base, the two axes, and the CW shaft (which is very thick for stability). I think the heaviest part of the Mach1 is 16lb, which is quite a bit less than my Atlas (which doesn't break down outside of the mount coming off the tripod).


You can get good portability with higher end mounts and higher capacities. I use the Atlas in a certain way. I have marked up everything, the mount, the dovetails, the scope rings, even my lens itself (tape on the body) so that I can just put everything together, rotate parts as necessary to get everything aligned identically every time, and setup is very quick and easy. 


The Sirius is a smaller version of the Atlas, basically, with a smaller capacity (30lb), lighter mount, and cheaper cost. If you want the most reliable and portable mount for the lowest cost, I would say look for a used Orion Sirius. It'll handle a 600mm lens and 5D III (and guide scope and camera and all the cables hanging off them), and you can usually find one for about $700 used. That isn't even $200 more than an AstroTrac, and it's more portable than the Atlas. For those who want to spend a little money as possible, but want some room to grow, I would offer that the Sirius is probably the best option. Intermediate imagers have used that mount (which is also upgradable with a belt mod) up to 20lb capacity with good results, so if you ever wanted to eventually move up to a larger OTA like an AT8RC or a small 6" newtonian, you could.


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## Schmave (Mar 2, 2015)

jrista said:


> I wouldn't use Lightroom for processing. Photoshop is significantly better, and there are a number of actions packages out there that can make things easier (Look for Carboni's Astro Actions).
> 
> 
> Ultimately, Photoshop isn't even the most ideal tool for astro processing. It's great for beginners as many beginners already have it, but if you end up serious about the hobby, I highly recommend looking into PixInsight. It's a program designed specifically for astro image processing, including integration (the stuff DSS does, only PI is WAY better at it.)
> ...



Thanks for the tips. I'll check out cloudy nights forums and see what they have to say.


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## Crosswind (Apr 11, 2015)

*IR sensitive sensor at daytime?*

Hi there, I have a quick question to all people using cameras like the *60Da* or the like, which have no IR blocking.

How would the images look like at daytime as it is not recommended to take photos at that time with such cameras...? If they look a lot weaker than they would taken with a normal camera, could it be a possibility to convert them into Black&White to still get good images at daytime? How much difference is there

thx in advance


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## jrista (Apr 12, 2015)

The 60Da is explicitly designed as a dual-mode camera. It can work for regular "terrestrial" photography, or astrophotography. As such, it's increased sensitivity to H-alpha is not that much improved over a stock Canon DSLR, and significantly lower than a full astro-modded Canon DSLR (which has the IR filter removed entirely and usually replaced with a square IR/UV cutoff filter.) 


You should get better Ha exposure depth with a 60Da than an unmodded camera, but the changes in that camera's design by no means make it unusable for daytime photography. 


The new Nikon D810a, on the other hand, was explicitly designed as an astrophotography camera. It is not recommended for use as a daytime photography camera. It's price is so prohibitive that it's not even recommended as an astro camera, as for hardly any more (and in some cases possibly even less) you can get a proper cooled mono astro CCD camera with filter wheel, and get significantly better exposures than any DSLR.


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## StudentOfLight (May 5, 2015)

jrista said:


> The 60Da is explicitly designed as a dual-mode camera. It can work for regular "terrestrial" photography, or astrophotography. As such, it's increased sensitivity to H-alpha is not that much improved over a stock Canon DSLR, and significantly lower than a full astro-modded Canon DSLR (which has the IR filter removed entirely and usually replaced with a square IR/UV cutoff filter.)
> 
> 
> You should get better Ha exposure depth with a 60Da than an unmodded camera, but the changes in that camera's design by no means make it unusable for daytime photography.
> ...


A few years back, when my previous employer bought a high-end FLIR camera I was sent on a Infrared-Thermography course. We were taught that most IR light does not pass through glass, only near-IR. Based on that, would I be mistaken in thinking that it is a bit of a waste using specialized IR cameras with conventional lenses? Wouldn't the glass likely absorb a huge proportion of the incoming IR thereby nullifying the gains on the sensor side? Would these dedicated astro camera sensors be more suited to mirror-type telescopes?


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## jrista (May 6, 2015)

StudentOfLight said:


> jrista said:
> 
> 
> > The 60Da is explicitly designed as a dual-mode camera. It can work for regular "terrestrial" photography, or astrophotography. As such, it's increased sensitivity to H-alpha is not that much improved over a stock Canon DSLR, and significantly lower than a full astro-modded Canon DSLR (which has the IR filter removed entirely and usually replaced with a square IR/UV cutoff filter.)
> ...




The visible spectrum stretches from about 380nm to about 750nm. Standard glass will usually pass light from about 400nm to 900-950nm or so. Depending on the materials, various kinds of optical glass will pass more or less IR. Near Infrared stretches to around 1400nm. Most IR photography works in the MUCH nearer IR range, 750-900nm (not even as deeply as 900nm even), so I don't see why using standard lenses would be a problem. If you want to work deeper into the near IR spectrum, then you might need higher quality or different kinds of lenses. 


Also remember that there are reflecting telescopes. With mirrors, any part of the electromagnetic spectrum that the mirror material is not transparent to will be reflected. Near IR imaging (which is sometimes done in astrophotography) is usually done with some kind of pure reflecting telescope, newtonians or RCs.


----------



## jrista (May 10, 2015)

I wrapped up the first draft of the design for my astrophotography site, Nascent in Nebulosity:





Honestly not sure when I'll have time to turn it into an actual web site, but overall, I'm happy with the progress on the design. Here is the landing screen and transition to site animations:

http://i.imgur.com/JqLAfVU.gif

The initial screen:


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## Schmave (May 12, 2015)

The website looks really good jrista! Thanks for sharing.


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## East Wind Photography (May 13, 2015)

Yes I expect to see all of those cool tips for taking better astrophotos along with image processing techniques. Hell maybe even a store front for pixinsight services. We take the shots and pay for you to process for us.


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## jrista (May 16, 2015)

Hah, interesting idea about the PixInsight "storefront". I don't know that I'd ever have that much free time. It takes a lot of time to process an image. Also, processing is where each photographer's personal style comes out, and I wouldn't want to take that away from people. 

I guess one thing I could offer is an integration service...just take their RAW files, darks, biases and flats, and integrate the data into .fits and .tiff files, then send em back. That's mostly just CPU time, and maybe an hour or two of my own time.


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## jrista (Jun 11, 2015)

So, I FINALLY got a full clear night two nights ago. Well, clear until about 3:30 am, when the waning half moon became a problem. Anyway...I haven't imaged in about two months, maybe longer. I gathered 25 7-minute subs at ISO 400 with the 5D III and 600mm. 

The data was so good, this...is a SINGLE SUB (I am currently taking dark frames as my sensor temps are about 6-10 degrees higher than they were the last time I imaged, so no final image yet):


----------



## meywd (Jun 11, 2015)

jrista said:


> So, I FINALLY got a full clear night two nights ago. Well, clear until about 3:30 am, when the waning half moon became a problem. Anyway...I haven't imaged in about two months, maybe longer. I gathered 25 7-minute subs at ISO 400 with the 5D III and 600mm.
> 
> The data was so good, this...is a SINGLE SUB (I am currently taking dark frames as my sensor temps are about 6-10 degrees higher than they were the last time I imaged, so no final image yet):



Man that's amazing, very beautiful capture, just to be on the same page, when you say single sub you mean a single frame?


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## jrista (Jun 11, 2015)

Yes, single frame. In astro, a sub means "sub exposure", since you usually take many individual exposures and stack them together (integrate them) to produce a higher SNR final image.

I have 25 subs just like this one, so once I integrate, the image should be pretty amazing with quite a lot of detail at full size (this is maybe 1/3rd size).


----------



## meywd (Jun 11, 2015)

jrista said:


> Yes, single frame. In astro, a sub means "sub exposure", since you usually take many individual exposures and stack them together (integrate them) to produce a higher SNR final image.
> 
> I have 25 subs just like this one, so once I integrate, the image should be pretty amazing with quite a lot of detail at full size (this is maybe 1/3rd size).



Wow really amazing, keep up the good work man, love it.


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## NancyP (Jun 12, 2015)

jrista, I am seriously impressed.


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## Click (Jun 12, 2015)

Beautiful shot, Jon.


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## jrista (Jun 12, 2015)

Thanks, guys!  

Hopefully tonight, I'll be able to produce the proper integrated version. Had a tough time getting darks matched well enough in temperature. I am finally integrating now, though, and I should be able to produce a much better, full resolution version tonight. Hoping it will help me pull out more of the faint nebulosity in the outer parts of Lagoon.


----------



## jrista (Jun 14, 2015)




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## Don Haines (Jun 14, 2015)

Nice image.... A source of inspiration to us lesser mortals.....


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## meywd (Jun 14, 2015)

Great shot Jon, amazing details.


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## Click (Jun 14, 2015)

Awesome. Well done Jon.


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## Don Haines (Jul 15, 2015)

and on a less serious note...... Nasa releases the first detailed images of Pluto.....


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## Click (Jul 15, 2015)

Don Haines said:


> and on a less serious note...... Nasa releases the first detailed images of Pluto.....




LOL ;D ;D ;D


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## Don Haines (Jul 15, 2015)

Click said:


> Don Haines said:
> 
> 
> > and on a less serious note...... Nasa releases the first detailed images of Pluto.....
> ...



On a serious note.... it takes ten years to get there, is perfectly on target, everything works after ten years in space, fantastic images captured, and beamed back to earth...... NASA should be proud... this is a major accomplishment that means far more than just the images... Congratulations!


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## NancyP (Jul 16, 2015)

1. who cares whether Pluto got demoted, it still looks darn good. 

2. Congratulations, jrista, on your latest.


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## Sunnystate (Jul 16, 2015)

Just WOW!



jrista said:


>


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## Maximilian (Jul 16, 2015)

Great job, Jon!


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## Maximilian (Jul 16, 2015)

Don Haines said:


> and on a less serious note...... Nasa releases the first detailed images of Pluto.....


*lol* ;D ;D ;D
da-da-da, da-dada, da-dada (trying to intonate "The Imperial March")


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## East Wind Photography (Jul 17, 2015)

Maximilian said:


> Don Haines said:
> 
> 
> > and on a less serious note...... Nasa releases the first detailed images of Pluto.....
> ...



Funny how that old tech, well just looks old after seeing jrista's shots from here on earth. I hope the next ones have a 600 F4L IS II on board.


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## jrista (Jul 17, 2015)

Don Haines said:


> and on a less serious note...... Nasa releases the first detailed images of Pluto.....



Haha! Nice!


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## jrista (Jul 17, 2015)

Here are some more (including a further enhanced version of the Lagoon one):

M20 & M8 (Lagoon and Trifid):






Milky Way (bit of interference from light clouds):





Snake Nebula and region:





Blue Horsehead:





Eagle and Omega (Swan) Nebulas (M16 and M17):





Also reprocessed my old Andromeda data, whole new (and much more realistic) look:






A guy on Cloudy Nights shared his Trifid data, which turned out to be pretty good:






And my latest, Veil Nebula, which is still a WIP...only got half the data I wanted, plus there were light high clouds moving earlier in the night that left brown muck throughout a lot of the field:


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## Don Haines (Jul 17, 2015)

jrista said:


> Here are some more (including a further enhanced version of the Lagoon one):
> 
> M20 & M8 (Lagoon and Trifid):
> 
> ...



WOW, WOW, WOW, WOW, WOW, WOW, WOW, and WOW

These are inspirational!!!!!

Fantastic!!!!!!!


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## Click (Jul 17, 2015)

Awesome. Beautiful images, Jon. 8)


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## meywd (Jul 17, 2015)

Don Haines said:


> jrista said:
> 
> 
> > Here are some more (including a further enhanced version of the Lagoon one):
> ...



+1 stunning


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## rpt (Jul 17, 2015)

meywd said:


> Don Haines said:
> 
> 
> > jrista said:
> ...


Absolutely fantastic!


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## jrista (Jul 17, 2015)

Thanks, Guys!  Hopefully that won't be the last this year...weather has been pretty wild, never know when the night might clear. I've even missed a couple because I thought it was going to be cloudy, and early when I poked my head out it was...only to have it clear later on after I'd mostly gone to bed (and at that point, I can't go out and set up...not on weekdays.)


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## Alejandro (Jul 17, 2015)

jrista said:


> While you can barely fit a 600/4L and 5D III on the Star Adventurer, it is not recommended. The rule of thumb for imaging is to use only half the rated capacity. More than that, and your tracking accuracy will suffer, which will affect your stars. You shouldn't put more than 5-6 lb on the Star Adventurer for best results. You might get away with 7-8lb, but with longer lenses your star profiles will suffer (you'll have bloated stars, and you'll lose the benefits of the increased resolution of a large lens like the 600mm f/4).




I'm sorry to be asking this... so is the Star Adventurar an extremely well designed barn door tracker? I mean, you can't track the stars in exposures longer than 2-5 minutes @ 200mm or something like 30 seconds on 600mm, correct?


----------



## jrista (Jul 17, 2015)

Alejandro said:


> jrista said:
> 
> 
> > While you can barely fit a 600/4L and 5D III on the Star Adventurer, it is not recommended. The rule of thumb for imaging is to use only half the rated capacity. More than that, and your tracking accuracy will suffer, which will affect your stars. You shouldn't put more than 5-6 lb on the Star Adventurer for best results. You might get away with 7-8lb, but with longer lenses your star profiles will suffer (you'll have bloated stars, and you'll lose the benefits of the increased resolution of a large lens like the 600mm f/4).
> ...



The Star Adventurer with the Equatorial Wedge tracks right ascension in sidereal time, so it is definitely not just a glorified barn door. It would be a full equatorial, albeit without any powered DEC tracking (so it will only track in RA, and DEC pointing is manual.)

With an appropriate payload, and good polar alignment, you should be able to track for minutes. With wider field lenses, including a 200mm, you could probably track for 10 minutes, but you really wouldn't need to (the wide lenses suck in a lot of light per pixel.)


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## jrista (Jul 19, 2015)

Here's another one. This time, the Gamma Cygni region:






Very complex region, lots of emission nebula (both hydrogen and oxygen), lots of reflection nebula, lots of dark nebula. Star clusters. This one was a tough process. Little bit less than three hours integration time.


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## Click (Jul 19, 2015)

Stunning picture, Jon.


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## V8Beast (Aug 25, 2015)

These could just be the most stunning images I've ever seen on Canon Rumors.....and I've seen some brilliant work on Canon Rumors.

Great stuff, Jon. Please keep the images coming


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## jrista (Aug 25, 2015)

Thank, Click! Thanks, V8, truly.

I'll keep em comin if I can get em. Weather in Colorado has been really bad this year. Hardly had any clear nights. Been trying through the couple of clear nights we have recently had, but they were riddled with smoke that blew in from California, so still nothing. Now the moon is full, so it will be a couple more weeks before I even potentially get another chance, if the skies are clear (which is unlikely.)


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## telemaq76 (Aug 27, 2015)

here is a picture of M33 galaxie taken with a canon 1dx+400 f5.6 + skytracker
89 pictures with darks, bias, flats stacked with DSS and finally photoshop


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## telemaq76 (Aug 29, 2015)

any of you tried or heard about new 5ds for astro? ;D


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## jrista (Sep 12, 2015)

There isn't a whole lot of excitement in the astro community for Canon cameras these days. A couple guys promote them a lot, like Roger Clark, but most people are much more interested in the newer entry-level Nikon DSLRs, like the D5300 and D5500. They have lower dark current, higher resolution, lower noise at low ISO. Canon cameras are rarely used ISO 800 and heavily clipped stars are fairly common, but people are using Nikon's as low as ISO 200 (and in a few cases ISO 100) for the increased DR. 

The D800, D810, and D810a, with black point clipping hacks and astro modding on the former two, have garnered FAR more interest among higher end DSLR imagers than the 5Ds. The guys I know who image with them produce some of the most amazing astro images I've ever seen. 

If there was any field where read noise and dynamic range mattered more than landscape photography, astrophotography is it. By a long shot.


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## V8Beast (Sep 16, 2015)

Got any UFO pics ;D?


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## East Wind Photography (Oct 27, 2015)

jrista said:


> There isn't a whole lot of excitement in the astro community for Canon cameras these days. A couple guys promote them a lot, like Roger Clark, but most people are much more interested in the newer entry-level Nikon DSLRs, like the D5300 and D5500. They have lower dark current, higher resolution, lower noise at low ISO. Canon cameras are rarely used ISO 800 and heavily clipped stars are fairly common, but people are using Nikon's as low as ISO 200 (and in a few cases ISO 100) for the increased DR.
> 
> The D800, D810, and D810a, with black point clipping hacks and astro modding on the former two, have garnered FAR more interest among higher end DSLR imagers than the 5Ds. The guys I know who image with them produce some of the most amazing astro images I've ever seen.
> 
> If there was any field where read noise and dynamic range mattered more than landscape photography, astrophotography is it. By a long shot.



I grabbed a 5dsR the other day and once this full moon abates, I will give it a shot. Astro is not my primary use but will see how it holds up to something big, bright, and stacked.


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## jrista (Nov 1, 2015)

East Wind Photography said:


> jrista said:
> 
> 
> > There isn't a whole lot of excitement in the astro community for Canon cameras these days. A couple guys promote them a lot, like Roger Clark, but most people are much more interested in the newer entry-level Nikon DSLRs, like the D5300 and D5500. They have lower dark current, higher resolution, lower noise at low ISO. Canon cameras are rarely used ISO 800 and heavily clipped stars are fairly common, but people are using Nikon's as low as ISO 200 (and in a few cases ISO 100) for the increased DR.
> ...



The moon should do fine with the 5DsR. Because it is big and bright, you'll be able to get a very strong signal and noise won't be a problem.

It's the very faint deep sky astrophotography stuff that Canon cameras have more of a problem with. The Nikon cameras really reign supreme these days, with their exceptional noise handling. The Sony A7s has become a bit of a cult favorite with astrophotographers these days as well. It's small, light weight, and there is a project going on to see if it is possible to cool them with peltiers on the cheap, without having to be invasive into the camera body, and without needing a large enclosure. Sony's internal layout results in multiple metallic connections to the body, which improves heat conductance, making a simpler peltier cooler easier to do. 

If Canon someday addresses their readout noise issues, I'm sure they will surge back to the forefront. They have the most software compatibility for astro imaging, which is a big bonus (although Nikon has caught up almost entirely). Sony currently lacks a lot of software support because of their limited SDK, although that is slowly improving.


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## jrista (Nov 1, 2015)

Haven't posted here in a while. Here is another of my more recent images. California Nebula in this case, in the constellation Perseus. This nebula is not all that far from the Pleiades cluster:











This is an integration of 155x150s subs, for a total of 6.5 hours of exposure time. Imaged at a very dark site, skies 21.36mag/sq", over three separate nights. Processed with PixInsight.


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## jrista (Nov 1, 2015)

Another more recent image. Elephant Trunk nebula in IC1396. This is in the constellation Cepheus, neighbor of Cassiopeia around the north celestial pole. 










This is an integration of 161x150s subs for a total of 6.7 hours of exposure time. Also imaged at a dark site, 21.36mag/sq", over four separate nights. Processed with PixInsight.


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## Click (Nov 1, 2015)

Beautiful shots, Jon.


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## telemaq76 (Nov 7, 2015)

New version of my previous andromeda galaxy
same pictures but stacked with iris and better process





57*2 min, with 1dx+500 f4 +neq6pro


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## Click (Nov 7, 2015)

Awesome. Well done telemaq76.


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## scottkinfw (Nov 7, 2015)

A pic to be proud of!



telemaq76 said:


> New version of my previous andromeda galaxy
> same pictures but stacked with iris and better process
> 
> 
> ...


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## telemaq76 (Nov 7, 2015)

thank yes i m proud of it 8) . but i wish i can do better if i have more time . but i live i a cloudy country :'(


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## nda (Nov 7, 2015)

V8Beast said:


> Got any UFO pics ;D?


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## telemaq76 (Nov 23, 2015)

few clear skies last days, only clouds, just had one hour to shoot Orion

22x2 minutes + DOF stacked with Iris


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## Click (Nov 23, 2015)

telemaq76 said:


> few clear skies last days, only clouds, just had one hour to shoot Orion
> 
> 22x2 minutes + DOF stacked with Iris



Awesome. Great shot. 8) I really like this picture. Well done.


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## scyrene (Nov 23, 2015)

telemaq76 said:


> thank yes i m proud of it 8) . but i wish i can do better if i have more time . but i live i a cloudy country :'(



This is the biggest problem! I'd invest a lot more time and money into astrophotography if it wasn't for the fact we get one good, clear night only once every two weeks or so.


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## East Wind Photography (Nov 25, 2015)

scyrene said:


> telemaq76 said:
> 
> 
> > thank yes i m proud of it 8) . but i wish i can do better if i have more time . but i live i a cloudy country :'(
> ...



And the moon kills it the rest of the time. I've found it necessary to avail myself at any window of opportunity...much to the dislike of my family.


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## East Wind Photography (Nov 25, 2015)

jrista said:


> Haven't posted here in a while. Here is another of my more recent images. California Nebula in this case, in the constellation Perseus. This nebula is not all that far from the Pleiades cluster:
> 
> 
> 
> ...



You always seem to have the perfect focus. What is your process for getting there? I know you often use your 600 and I'm curious to see where I can improve on that.


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## jrista (Nov 26, 2015)

East Wind Photography said:


> You always seem to have the perfect focus. What is your process for getting there? I know you often use your 600 and I'm curious to see where I can improve on that.



I use software focus assist tools. For the 5D III and 600mm lens, I use BackyardEOS (BYE). There is a frame and focus module in that program that pipes in the live view feed. I just find a medium bright star, put it about a third of the way to the edge from the center, and use the 5x zoom mode to view the star at full size. I then center the star in a little readout, which displays the star's FWHM (full width at half maximum). BYE has built-in controls to adjust the lens' focus, electronically so you don't have to touch the lens and cause vibrations. These controls have coarse, medium and fine control in both directions, and I just use them to adjust focus until the FWHM drops to and settles at a minimum. 

Because the lens is so large, I have to regularly focus throughout the night. It can contain a lot of heat, and it takes time for that heat to dissipate, and all the glass results in a fairly significant focus shift. I will focus every frame (usually 5-10 minutes) early, then every 2-3, then maybe once an hour, until the lens settles. 

I have other software for my 8" RC telescope. SGP or Sequence Generator Pro, is more advanced than BYE. I purchased a Moonlite CSL 2.5" focuser for the 8" RC, a robotic focuser with support for computer control via ASCOM. With SGP, I can configure it to automatically focus, and do so every few frames. SGP has a whole bunch of other advanced features...automatic framing, the ability to reframe to the same object with pixel accuracy on subsequent nights, it can automatically handle meridian flips, it can synchronize with guiding, etc. You can basically automate the whole imaging process with it. Autofocus with SGP will usually get even better focus than I can when manually focusing with BYE.


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## MrToes (Nov 26, 2015)

Don Haines said:


> and on a less serious note...... Nasa releases the first detailed images of Pluto.....



LOL!!!


----------



## East Wind Photography (Nov 28, 2015)

jrista said:


> East Wind Photography said:
> 
> 
> > You always seem to have the perfect focus. What is your process for getting there? I know you often use your 600 and I'm curious to see where I can improve on that.
> ...



Ive messed around with bya but never actually used it in the field. The AF section is particularly interesting. I will give it a shot next window of opportunity. Ive noticed these lenses really take time to adjust to temperature. Not only AF is affected but lens shape as well. At first i just thought the mechanics would drift a bit being aimed up almost all night. But it seemed to calm down after a few hours. Ive started the acclimation process way ahead of time...however even so, its not as rapid as say a newtonian mirror. The autofocus in sgp sounds like the best way since it can be inserted in the workflow and yields less human error.

Its too bad Canon doesnt include the ability to AF on a star at 10x. Seems fairly trivial but i guess there are other factors to consider in the firmware.


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## telemaq76 (Jan 7, 2016)

First try with my new canon 700d astrodon on IC 434
the best night for monthes..and my neq6pro died 3 days ago
good for me i still have my small ioptron skytracker
only 45 seconds exposure iso-1600 f5.6
with canon 400 f5.6L
but 372 pictures, 295 darks, 28 flats and 86 offsets


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## Click (Jan 7, 2016)

Great picture. Well done, telemaq76.


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## jrista (Jan 7, 2016)

telemaq76 said:


> First try with my new canon 700d astrodon on IC 434
> the best night for monthes..and my neq6pro died 3 days ago
> good for me i still have my small ioptron skytracker
> only 45 seconds exposure iso-1600 f5.6
> ...



Wow! That is actually quite good. Those 372 subs really did the trick!! I think 295 darks is beyond excessive...you would have been fine with 50 of them, from a statistical standpoint. It is better if you get hundreds of biases (offsets) rather than hundreds of darks, since the biases are used to calibrate everything, while the darks are only used to calibrate the lights. 

Anyway, great result for 45 second subs. Good, accurate color. You have a gradient...you can fix that with GradientXterminator in Photoshop, or with PixInsight. Starts are a bit bright, there are ways of dealing with that. Nice job!


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## telemaq76 (Jan 8, 2016)

thanks for your feedback i appreciate. After doing my 372 pics, i went to sleep, letting the camera working for the darks, that s why i have lots of them. sometime i read it s necessary to have same amount of dark than light. And i wonder something about offset. Offset are included in the darks anyway then why doing them


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## telemaq76 (Jan 14, 2016)

first try on orion nebula with my new astrodon body, 700d
not a lot of differences with standard camera on orion
i used to shoot astro with my regular 1dx.I just notice the gap in dynamic. Never had any problem on orion with the 1dx. With the crop sensor, the center of nebula is quickly overexposed.


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## jrista (Jan 14, 2016)

telemaq76 said:


> first try on orion nebula with my new astrodon body, 700d
> not a lot of differences with standard camera on orion
> i used to shoot astro with my regular 1dx.I just notice the gap in dynamic. Never had any problem on orion with the 1dx. With the crop sensor, the center of nebula is quickly overexposed.



Nice work, good color and detail.

Regarding DR, depending on the image scale yes, it's possible the smaller pixels will saturate faster than a 1D X would.


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## Click (Jan 14, 2016)

telemaq76 said:


> first try on orion nebula with my new astrodon body, 700d
> not a lot of differences with standard camera on orion
> i used to shoot astro with my regular 1dx.I just notice the gap in dynamic. Never had any problem on orion with the 1dx. With the crop sensor, the center of nebula is quickly overexposed.



Beautiful colours. Nicely done, telemaq76.


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## telemaq76 (Jan 16, 2016)

first try with my new 700d astrodon +cls-cdd filter
i choosed the flaming star nebula
33x225 sec+dof


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## Click (Jan 16, 2016)

Awesome. Well done, telemaq76.


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## jrista (Jan 18, 2016)

Nice work, Telemaq. That's a real tough target...lots of faint Ha.


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## jrista (Jan 18, 2016)

My latest image, second of 2016, the Witch Head Nebula. This is an integration of 84x300s (7 hours) subs from a dark site (~21mag/sq", yellow zone...my dark site has lost over a stop of it's original darkness, about .6-.7 mag/sq", in the last 13 months :thumbsdown: ). Image acquisition with Canon 5D III (unmodded), Canon EF 600mm f/4 L II @ f/4.5, ISO 800 (~1/4 histogram subs, with the exception of a handful of early evening subs, which were around 1/3rd histogram).

Processed entirely in PixInsight, using a synthetic luminance process where the L channel is extracted from the RGB and processed separately with deconvolution and additional detail-enhancing steps, and the RGB is processed with more heavy noise reduction.


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## Click (Jan 18, 2016)

Stunning Image. It's always a pleasure to look at your pictures, Jon.


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## telemaq76 (Jan 23, 2016)

insane work jrista, i love that witch head nebula. I already tried to target it but i see nothing on my picture lol. Maybe one day if i m lucky enough to have a perfect clear sky , almost impossible in my cloudy country

Here is a new version of my flaming star nebula, with better colors i think
same picture same previous one, just different editing and framing


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## Click (Jan 23, 2016)

telemaq76 said:


> Here is a new version of my flaming star nebula, with better colors i think
> same picture same previous one, just different editing and framing




This one looks better. Beautiful picture. Well done, Sir.


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## cpcw06 (Jan 24, 2016)

These pictures sure make me want to give astrophotography a try! Very nice!


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## telemaq76 (Jan 25, 2016)

a new picture of bubble nebula.
not enough time to make something better.
hope i can shoot it again soon with more time


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## jrista (Jan 26, 2016)

Looks good. Bubble itself is bright, but the whole region is packed with hydrogen nebula, and you picked that up pretty well. You also picked up M52 in the same frame (which must be huge...what scope and camera are you using?)


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## telemaq76 (Jan 28, 2016)

thank jrista, i used a canon 500 f4 IS, on my new canon 700d astrodon


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## telemaq76 (Feb 4, 2016)

new picture of soul and heart nebula. happy with my picture but i need a better process when i ll have time.
23x5 min + dof...700d astrodon+cls-ccd+70-200 2.8 is II+neq6pro


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## Reality Merely Illusion (Feb 4, 2016)

Wonderful thread and thanks to everyone who posts pictures here!, very enjoyable pictures

This last decade(or two) has been incredible !


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## Click (Feb 5, 2016)

Awesome. Great shot, telemaq76.


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## telemaq76 (Feb 6, 2016)

thank you guys


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## telemaq76 (Feb 13, 2016)

after weeks and weeks only cloudy and rainy nights, finally a bit time with "not too bad" sky . I tried the rosetta nebula. 26 subs of 4 minutes + dof . 
really love the 700d astrodon +cls-ccd filter, it really does the job


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## rpt (Feb 13, 2016)

telemaq76 said:


> after weeks and weeks only cloudy and rainy nights, finally a bit time with "not too bad" sky . I tried the rosetta nebula. 26 subs of 4 minutes + dof .
> really love the 700d astrodon +cls-ccd filter, it really does the job


Lovely!


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## Click (Feb 13, 2016)

telemaq76 said:


> after weeks and weeks only cloudy and rainy nights, finally a bit time with "not too bad" sky . I tried the rosetta nebula. 26 subs of 4 minutes + dof .
> really love the 700d astrodon +cls-ccd filter, it really does the job



Great shot, telemaq76. 8) Well done.


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## telemaq76 (Feb 20, 2016)

new pictures taken few days ago, sky not great with moon 

m81 and 82




and M51


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## Click (Feb 20, 2016)

telemaq76 said:


> new pictures taken few days ago, sky not great with moon



Awesome. Beautiful shots, telemaq76.


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## cazza132 (Feb 20, 2016)

Our galactic core. Full spectrum modded 6D + Zeiss 135mm f2.0
https://www.flickr.com/photos/[email protected]/24395692850/


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## Click (Feb 20, 2016)

Stunning. Well done, cazza132


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## slclick (Feb 21, 2016)

telemaq76 said:


> first try on orion nebula with my new astrodon body, 700d
> not a lot of differences with standard camera on orion
> i used to shoot astro with my regular 1dx.I just notice the gap in dynamic. Never had any problem on orion with the 1dx. With the crop sensor, the center of nebula is quickly overexposed.



Ooh I love this, beautiful job.


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## telemaq76 (Feb 22, 2016)

superb shot cazza, like all your work

i tried a new picture of orion, with the moon 
with canon 500 f4 Is+ teleconverter 1.4 III


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## Bundu (Feb 22, 2016)

Absolutely great! I bought a celestron AVX mount with 8" newtonian scope last year. Only had one opportunity last year to use the mount with my 7dii and 100-400 ii with 1.4 iii. It was a nice dark site but as it was May Orion was very low on the horizon and with me not familiar with the equipment it took a long time to set up. Even then it was not perfect and I only got 7 usable subs, forgot about the darks before Orion was gone behind the dunes (Kgalakgadi transfrontier park). The photo is attached. I am going to Botswana the last week in March, a dark site again but full moon. And this time i want to use the 8" newtonian. It will be for 10 days so i will get to know my equipment and practise for future use! Any help will be appreciated. What filter to use to minimise the full moon? What settings on the 7dii. I am going to target Orion again so i can see if i get to improve from last year. On the software side i have byeos and dss.
Edit: Apologies, see this thread is for images only.


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## Click (Feb 22, 2016)

telemaq76 said:


> i tried a new picture of orion, with the moon
> with canon 500 f4 Is+ teleconverter 1.4 III



Awesome. Great shot, telemaq76.


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## cazza132 (Feb 22, 2016)

telemaq76 said:


> superb shot cazza, like all your work
> 
> i tried a new picture of orion, with the moon
> with canon 500 f4 Is+ teleconverter 1.4 III


Nice work telemaq76! What cam and mount were you running here? Thanks for compliments on my work


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## cazza132 (Feb 22, 2016)

The Great Orion Nebula, M42

Used my stock 6D rather than the full spectrum modded 6D.

Stock 6D, 70-200 f2.8L+2xTCII = 400mm, ISO3200, Shutter times: 20x2min, 16x30s, 16x8s, 12x3s. Was quite warm so dark frame subtraction was used (should have used the peltier cooler!). Astrotrac was used to track the stars.

All done in a bit over an hour in one session with 20 degree ambient temps (should have put the peltier cooler case on!) So had to hit the NR pretty hard on fainter areas - even after dark frame subtraction.


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## Click (Feb 22, 2016)

Stunning picture, cazza132


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## Bundu (Feb 22, 2016)

Cazza132, telemaq76
Stunning photos. If I can get mine half as good I will be extatic! I suppose to do that I must actually spend the time ;D


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## telemaq76 (Feb 22, 2016)

i m using a canon 700d modified astrodon with a cls-cdd filter. my mount is the skywatcher neq6pro
and my sky is very cloudy most of the time and lots of light pollution. 

new pic of ic434 , again with 500f4+1.4 III on canon 700da
62 subs of 2 minutes + dark, flats, offset
Iris + photoshop

with lots of moon just near orion, lens freezing and seeing very average


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## jrista (Mar 18, 2016)

Nice work, everyone! I'm glad to see more people doing astrophotography. It's challenging, but very rewarding. 

Here my latest two images. I've had bad weather since the beginning of January, when I made the Witchhead Nebula image. I had also gathered some data on Seagull Nebula on one of the same nights, however I only had about 3 hours of it. I usually try to get 8 hours these days, so I hadn't processed it until recently. I employed some more advanced NR and color processing techniques in PixInsight, and the result actually ended up really good:











Seagull has been on my list for a while. It's a very interesting region. I feel I could still bring out more details, but I would need the full 8 hours, and I won't get another chance to try and add more data until next year.

A week ago, I had my first clear night since the first week of January. I took advantage of the entire night and gathered data on three targets: Blue Horshead (adding another hour of data to the two hours and 20 minutes I had from last year), the Coma Cluster of galaxies (tough region, very faint, little color), and a region I've been after for over a year, and one that has become one of my favorites: The Christmas Tree Cluster and Nebula region:










This is one hell of an amazing field. It's PACKED with objects, a lot of which I was not aware were in there until I started processing the image. I produced a plate solved and annotated version as well:


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## Click (Mar 18, 2016)

Great pictures, Jon. I'm always impressed by your work.


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## alexthegreek (Mar 18, 2016)

Here's my 2 cents!The great orion nebula of course!An easy target for beginners like me!90x1 min exposures 200mm 2.8 @ iso 800 + 20x5 sec for the core with a stock 500d on a skywatcher star adventurer mount.No darks flats or bias.What do you guys think?Should I be getting more of that faint stuff around the nebula with 90 mins of exposure?Should I go for more or will I be wasting my time?


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## Click (Mar 19, 2016)

Awesome. Well done, alexthegreek.


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## alexthegreek (Mar 23, 2016)

Thanks Click!By the way this is a 800% crop of another image.Does anyone know why I get these black dots?They're all over the place!It gives the image this almost honeycomb appearance.I oversharpened the image so it is easier for you to see.


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## jrista (Mar 23, 2016)

alexthegreek said:


> Thanks Click!By the way this is a 800% crop of another image.Does anyone know why I get these black dots?They're all over the place!It gives the image this almost honeycomb appearance.I oversharpened the image so it is easier for you to see.



This is what I call "webbing" (as it often looks like cobwebs), and is usually an artifact of processing. Most often deconvolution and noise reduction. Can you explain how you processed the image?


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## alexthegreek (Mar 23, 2016)

jrista said:


> alexthegreek said:
> 
> 
> > Thanks Click!By the way this is a 800% crop of another image.Does anyone know why I get these black dots?They're all over the place!It gives the image this almost honeycomb appearance.I oversharpened the image so it is easier for you to see.
> ...


Thanks for the reply jrista!Im afraid I can't be very specific about proccesing as this image was done a couple of months ago plus I don't have a certain way of doing things except that I make tiffs with acr then stack with dss and continue with photoshop for stretching.I also use carboni's actions plus nik's local contrast and detail enhancer.I don't have a system I just do something and if I like it I keep the changes and carry on.A bad way to post proccess for sure!I don't think I used calibration frames either.Here is the full image


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## StudentOfLight (Mar 28, 2016)

Carina Nebula - from the backyard (i.e. still in the city)

Canon 5D Mark-III, Tamron 70-200 f/2.8 (No-tracking)
15 x 2s @ f/3.2, ISO 1600


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## rfdesigner (Mar 29, 2016)

StudentOfLight said:


> Carina Nebula - from the backyard (i.e. still in the city)
> 
> Canon 5D Mark-III, Tamron 70-200 f/2.8 (No-tracking)
> 15 x 2s @ f/3.2, ISO 1600



That's not a bad image, well done. To my eye's I thought you'd left some data on the table, I downloaded the jpeg and had a play at levels, curves etc then I realised you've hit a limit as you don't seem to have used "flats"

So I ran the image through IRIS and used the subsky command which can flatten an unevenly bright background, and then levelled the colour chanels to remove the remaining red glow and got the below image.

I think you could get this much better by using flats.. and it's probably your next step. (taking an image of a perfectly flat white object, 100% out of focus, and dividing your image frames by this flat image. it also leaves the bits of the image that should be brighter alone where subsky can't tell the difference between broad areas of nebula and skyglow)


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## StudentOfLight (Mar 29, 2016)

rfdesigner said:


> StudentOfLight said:
> 
> 
> > Carina Nebula - from the backyard (i.e. still in the city)
> ...


Thanks for the feedback, I reprocessed with a few more light exposures and some flat exposures. I'm looking to get out of the city in the next week or so, and I'll put more effort into those images.


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## rfdesigner (Mar 29, 2016)

getting there but I don't think your flats are doing what you need them to.. exactly what do you do with your processing?. what steps do you take and what order and what stacking program?


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## StudentOfLight (Mar 29, 2016)

rfdesigner said:


> getting there but I don't think your flats are doing what you need them to.. exactly what do you do with your processing?. what steps do you take and what order and what stacking program?


I used deep sky stacker, it crashed twice with using CR2 files so for speed sake I decided to try using converted JPG files instead. I know I should use CR2 but, if it keeps crashing then I'll never learn the interface. The program did warn that flats would not work properly as JPG uses lossy compression.

I went through the motions and stacked with DSS and adjusted exposure and saturation. I then saved as TIFF.

I then opened in GIMP, duplicated layer and used dodge blend mode. I then used selective curves per channel to try and maximize contrast in the region of of the image that interest me. Dial back red channel and bring blacks to a more neutral hue.

This is by no means the best way to process files as I used lossy compression at various points in the process for speed and personal convenience. This was just a DSS learning exercise for me. (Shooting in a light polluted city) I will try to get better quality exposures and darker skies in the coming few days when the weather clears up.


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## rfdesigner (Mar 29, 2016)

StudentOfLight said:


> rfdesigner said:
> 
> 
> > getting there but I don't think your flats are doing what you need them to.. exactly what do you do with your processing?. what steps do you take and what order and what stacking program?
> ...



ah.. right don't use JPEG as it's non-linear, image calibration must be done with linear data, you can try 16 bit TIFF. (i.e. use DPP with all settings at default but the "linear" box ticked), then save as TIFF. Never the less getting to know the tool is time well spent.

Flats are awkward and can easily have slight gradients if you can get one fully corrected light frame then that's a good step forward.. so I would take a single CR2 or TIFF light frame one CR2/TIFF flat. You should get a much better (flatter) background.

Also take at least one fast dark (i.e. no signal) as canon cameras do not usually put out zero but are usually offset a little to the positive side which mucks up the division process. you can use this for pseudo dark frame as well as a bias (dark_flat) frame.

Again if that all works for "fixing" a single frame then you can worry about getting DSS not to crash with multiple frames... I suspect it's simply running out of memory.


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## StudentOfLight (Apr 4, 2016)

Eta Carina Nebula (Backyard practice, take 4)

Canon EOS 6D, with Tamron 70-200mm f/2.8 VC
491x Exposures: 3.2s at f/4, ISO 1600

Stacked in Deep Sky Stacker, 
16bit TIFF edited in Lightroom, 
8bit TIFF edited in GIMP (color, blends, etc)


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## rfdesigner (Apr 4, 2016)

StudentOfLight said:


> Eta Carina Nebula (Backyard practice, take 4)
> 
> Canon EOS 6D, with Tamron 70-200mm f/2.8 VC
> 491x Exposures: 3.2s at f/4, ISO 1600
> ...



getting better every time, nicely done.

starting to see a little lumpyness in the background, what calibration frames are you using?


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## Click (Apr 4, 2016)

StudentOfLight said:


> Eta Carina Nebula (Backyard practice, take 4)
> 
> Canon EOS 6D, with Tamron 70-200mm f/2.8 VC
> 491x Exposures: 3.2s at f/4, ISO 1600
> ...



Nice shot, Omesh. Well done.


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## StudentOfLight (Apr 4, 2016)

rfdesigner said:


> StudentOfLight said:
> 
> 
> > Eta Carina Nebula (Backyard practice, take 4)
> ...


The combination of good advice, practice, a taller stack and the 6D sensor all make for better results 

I set up my mount an hour before I started imaging so all shots were taken at the same temperature. I took many calibration shots immediately after my imaging session:
76x Dark frames
28x Offset/bias frames
24x Flat frames

Are these number of shots enough or excessive?

Regarding the flats... does DSS only used flats for vignette correction or does a lens' color transmission properties come into play as well? 
i.e. Do I need to use "full spectrum" light and a true neutral grey target or is okay to just get images of a flat surface which is evenly illuminated?

Do you have any advice on exposure settings?
For example Stellarium says Carina nebula is apparent magnitude 1.00 (extincted to 1.15)
Would it better for me to shoot brighter exposures? If I shot ISO 3200 instead of 1600, would the stacked image make better use of the DDS bit depth or would I just lose highlight detail?

Thursday night looks like the best conditions for me to head out of the city. Thanks again for all the help.


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## rfdesigner (Apr 4, 2016)

StudentOfLight said:


> rfdesigner said:
> 
> 
> > StudentOfLight said:
> ...



First up, you've got plenty of calibration frames. The amount you need is debatable, but you don't need 100s. I use equivelent of about 16 (I use double length darks, but let's not go there right now)

vignette:

DSS does not know anything about vignetting or optics or anything like that, all it's doing is pixel by pixel calibration, the optical correction drops out by the process.

It's not just vignette, your pixels will not all be exactly the same size (sensor lithography variations), your bayer matrix will not be 100% even, and of course there'll be dust specs and uneven illumination. All of this is covered by a flat frame.

Of course if your flat isn't flat then you're into a whole different set of problems.. getting a flat flat is something that can take quite a bit of trial and effort. Flats must also be made with the focus in the exact same position as the image frames. Same temperature is handy but less critical.

You can build yourself a flat field box to get a really flat field:

http://www.skyatnightmagazine.com/feature/how-guide/how-build-flat-field-box

Dark frames are good for removing pixel to pixel variations in the offsets imposed by the sensor, primarily variations in dark current.

The equation for each processed light frame is:

calibrated frame = (light frame - dark frame) / (flat frame - bias frame)

THEN once all your images are calibrated they are aligned then stacked.. DSS does not stack your lights then remove the darks.. some people fall in this hole and get very confused.

Image length / ISO:

Ignore what stellarium says about brightness, it can be out (ps the BV values are totally unreliable for dimmer stars).. Brightness in stars you want as magnitudes (as they're point sources), but for nebula you want as magnitudes per area, typ mag/sq arc second, and that is often much harder to find.. anyway.. it's a nebula, so it's very very dim.

Ideally on long tracked telescope shots you'd ensure your skyglow would swamp your readnoise.. you mention "mount", does that mean you're tracking?.. if so then it'll probably be down to drive (& guiding) and alignment accuracy.

if you're on a tripod, then as I think you know, just go as long as you can without smearing the stars, after smearing starts your SNR begins to fall. If stars are clipping take a few short shots and HDR them together (it will stop your bright stars from going white instead of the colours they really are)

ISO, 1600 or 3200 are about right, that's where you get minimum read noise for maximum DR on a 6D.

If you're still confused... don't worry, we've all been there, just ask again.


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## jrista (Apr 5, 2016)

rfdesigner said:


> First up, you've got plenty of calibration frames. The amount you need is debatable, but you don't need 100s. I use equivelent of about 16 (I use double length darks, but let's not go there right now)



I would say 16x is the minimum. With 16 subs you reduce random noise by a factor of 4x. That is ok, however you have to keep in mind that subtracting the master dark from each light is going to increase the random noise in the lights. I recommend no less than 25 darks for those who really don't want to stack a lot, and I usually recommend 49, which gives you a more reasonable 7x reduction in noise. That has a much smaller impact on the noise in each light, so small that it is swamped by all the other noise terms.


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## StudentOfLight (Apr 5, 2016)

I am using an equatorial mount from a Celestron 130EQ. It does not have a drive mechanism or GoTo functionality. The EQ mount makes it easier for me to make adjustments to keep my target in the frame, but my exposures are limited by focal length at the moment.


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## rfdesigner (Apr 5, 2016)

jrista said:


> rfdesigner said:
> 
> 
> > First up, you've got plenty of calibration frames. The amount you need is debatable, but you don't need 100s. I use equivelent of about 16 (I use double length darks, but let's not go there right now)
> ...



Everyone I come across has a different view on this, but I do take issue with "7x reduction in noise". that's really quite an unhelpful way of putting it. (regardless of the undeniably correct underlying truth)

Here's the maths which I think makes it easier to see:

16 dark frames => 1/sqrt(16) noise = 1/4 in the master dark.

Light noise + master dark frame noise = sqrt(1^2 + (1/4)^2) = 1.03077...

That's 0.03 magnitudes... so long as there's dithering between lights (i.e. you have to use image alignment to stack images)

make it 100 dark frames and you get 0.0054 magnitude degradation; 84 shutter actuations for .0246 magnitudes!

For someone starting out 16 darks mean they're not generating hundreds of shutter actuations chasing 0.03 magnitudes when they could pick up far more from getting other aspects right, like flats.

Once someone's producing work as good as yours with a setpoint cooled camera, then more darks can make some sense.


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## rfdesigner (Apr 5, 2016)

StudentOfLight said:


> I am using an equatorial mount from a Celestron 130EQ. It does not have a drive mechanism or GoTo functionality. The EQ mount makes it easier for me to make adjustments to keep my target in the frame, but my exposures are limited by focal length at the moment.



Ah that explains it.. then yes you're still limited by stars moving across your field of view.


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## jrista (Apr 5, 2016)

rfdesigner said:


> jrista said:
> 
> 
> > rfdesigner said:
> ...



I don't use a setpoint cooled camera. ;P I use an uncooled, unmodified 5D III. That camera is a pretty noisy camera in the grand scheme of things. Especially when imaging with sensor temps over 20C. Especially when it approaches 30C, dark current becomes the most significant source of noise (it can top 5e-/s/px, and if I get into the mid 30's C, it can get up to 8-10e-/s/px, and I don't even bother imaging at that point.) 

I also take great care to maximize the potential of my calibration. I used to be "sloppy" with my calibration, and that sloppiness showed in my results. Since I've started paying attention to every detail, it has improved my work considerably. I also chase every faint detail I can, so I guess extracting every last ounce out of my data and keeping the noise as low as possible does matter to me, where it might not for others. 

Personally, I agree about the actuation count, however I take a slightly different approach to minimizing noise. I use PixInsight to do all my pre-processing. I DO dither, however again, there is an efficiency factor there. I don't dither every frame, because dithering overhead can be high. I also dither less aggressively than some, because the higher the aggression, the longer the settle time, and the less actual open-shutter exposure time on target you get each night. I dither every 2-3 subs, depending on exactly how long they are. 

So, I tend to use 10-20 dark frames. However my dark frames are usually ~2x as long as the lights. PixInsight supports very accurate dark scaling, where by use of noise evaluation of each and every light frame, an optimized scale factor is used to match the master dark to the light. So with 20 frames that are 20 minutes long, scaled to 10 minute lights, it is more like having 40 frames, which is close enough to that 49 number I generally recommend. Also thanks to dark scaling, I do not need to have my darks 100% perfectly matched to the temperature of my lights. Some variation, I allow +/- 3C, is acceptable. Most of my lights fall into a couple of ranges of temperature, depending on the season, and I reuse darks for a while before recreating them. So, one need not expend a massive amount of shutter actuations needlessly creating 49 dark frames every time they image...not with the proper software. 

I also agree that getting biases right is important. My previous bias frame was made from 100 biases, which are super easy to get, and the bias signal does not change much, I used my last master bias for about a year. This last time, while doing various testing on my calibration frames, I ended up creating a 512-frame master bias, which was actually quite a bit less noisy than my previous 100-frame master bias, and revealed the PRNU of the sensor much better. It was also much better than using a superbias, which tends to obliterate fine column to column variations in PRNU that I am finding can and do show up in the deeper parts of the signal once the LP is offset. If your a signal hunter like me, this can matter (although 256 frames would probably be good enough...I only have 512 as I was using that data for an entirely different purpose.)

Flats are probably the area where most of the issues come from. Creating proper flats can actually be quite a challenge. Flats correct a lot of things, but because they are divided out they can also interfere with a lot of things. Dust motes can move, which can result in improper correction. Vignetting can change, which can result in improper correction. Gradients can change, which at the very least can require different kinds of pre-processing and integration (i.e. in PI, you can use flux equalization and percentile clipping to deal with flat gradients to a degree). Getting the right ADU count in a flat matters for proper correction. Etc.

So for a beginner, I would agree, focusing their efforts on flats would be more valuable. That said, acquiring darks is easy. And if you use a dark scaling algorithm, you do not actually need the darks to be ideally matched, and can usually reuse master darks for a good while before having to recreate them.


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## jrista (Apr 6, 2016)

Looks like one of my images is going to be published in Sky & Telescope Magazine:

http://www.canonrumors.com/forum/index.php?topic=29527.0

Second time, although the first image, which should be in the May edition next month, was a collaboration between me and another astrophotographer. This time, it's 100% my work.


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## rpt (Apr 6, 2016)

jrista said:


> Looks like one of my images is going to be published in Sky & Telescope Magazine:
> 
> http://www.canonrumors.com/forum/index.php?topic=29527.0
> 
> Second time, although the first image, which should be in the May edition next month, was a collaboration between me and another astrophotographer. This time, it's 100% my work.


Congratulations!


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## Click (Apr 6, 2016)

Congratulations, Jon!


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## rfdesigner (Apr 6, 2016)

jrista said:


> Looks like one of my images is going to be published in Sky & Telescope Magazine:
> 
> http://www.canonrumors.com/forum/index.php?topic=29527.0
> 
> Second time, although the first image, which should be in the May edition next month, was a collaboration between me and another astrophotographer. This time, it's 100% my work.



Congratulations, well deserved.


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## StudentOfLight (Apr 8, 2016)

jrista said:


> Looks like one of my images is going to be published in Sky & Telescope Magazine:
> 
> http://www.canonrumors.com/forum/index.php?topic=29527.0
> 
> Second time, although the first image, which should be in the May edition next month, was a collaboration between me and another astrophotographer. This time, it's 100% my work.


Congratulations Jon.


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## StudentOfLight (Apr 8, 2016)

From last night's imaging session...

1 - Carina Nebula - ISO 3200, f/4, 161x3.2s (2x drizzle)

2 - Large Magellanic Cloud (incl. Tarantula Nebula) - ISO 3200, f/2.8, 102x6s

I highlighted some fuzzy objects in the background of the LMC image. Where can I find out what these are? Not sure if they are globular clusters orbiting our galaxy or background galaxies.


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## Busted Knuckles (Apr 8, 2016)

On some other post on some other forum someone was noticing that the "film guy" was taking perhaps a single role of 36 exp film during the day vs. the "electronic guy" was spraying and praying 1000s of exposures - that the discipline of film forced from a cost/frame would lead one to be a more thoughtful photographer.

In reading JRISTA work up to imaging the night sky - there seems to be plenty enough discipline and plenty of thought goes into the effort - perhaps only available because of electronic image processing. (this is in addition to getting the tracking gear lined up, etc)

Check me off as impressed about the discipline and thoughtfulness that goes into each finalized image the Astro folks produce. 

Mike


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## rfdesigner (Apr 8, 2016)

StudentOfLight said:


> From last night's imaging session...
> 
> 1 - Carina Nebula - ISO 3200, f/4, 161x3.2s (2x drizzle)
> 
> ...



Well done.. another step forward there.

I think you mentioned you had stellarium, that's not a bad place to start when trying to identify the fuzzies.

I hope you're saving your stacked images (pre-postprocessing) as you'll want to go back and reprocess them in due course and not having to restack is good, although ideally you should keep your raw files too as you can improve your stacking process as well.

Producing images like this is a spiral, you get basic images, then you get stacking, then maybe upgrade the mount to take longer images, then the lens/telescope, then the processing software, then the location you're imaging from then back to the mount as you realise you can take even longer images, then change to scope to get better reach then, narrowband filters, then... you get the picture.

One word of advice.. if you want to spendany cash, bankrupt yourself for the mount and make do with everything else. a point and shoot on a great mount will surpass any scope on a lousy mount. The two main parameters you should look for are load capacity and periodic error.

Right now I have a fullerscope MkIV.. ancient mount, but huge load capacity and I've got the tracking reasonably good.. however I want to upgrade to this: http://www.mesu-optics.nl/mesu200_en.html

in the meantime I'm still trying to find time to build my observatory.


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## jrista (Apr 20, 2016)

As I was going through my massive volumes (terrabytes) of old data, I fond some data from one of my original Pleiades images. Back when I first acquired this data, I gathered a couple nights worth in September 2014, and processed about 3h30m of data. Back then, I was still just a beginner, and my skill with processing images, which I was doing partly in PixInsight and partly in Photoshop, was far more primitive.

The original image was one of my best at the time:






The Pleiades - 3.5hr - Canon 5D III, 150s @ ISO 400 | PixInsight (linear) & Photoshop (non-linear)





When I first processed this, I was a bit surprised to find a bunch of dust details in the area of space around the Pleiades itself. I never expected to get enough signal to do anything with those details, and I set about trying to bring them out. The very high noise added by light pollution limited my options with only 3.5hr worth of data, however. So I set about gathering more data, and for the next three months, through November 26th 2014, I acquired a total of about 11 hours of data.

I tried to process the entire data set a couple of times, and each time I had issues with severe complex gradients that I was unable to overcome at the time with my existing processing (we had some wildly different weather phenomena throughout those three months.) It was also at the end of 2014, December 23rd, that I found and started using a dark site to do all my wide field imaging. The dark site produced vastly superior results in far less time (I was starting to average 9-10 hours per integration from my back yard, and often even that much still did not produce good results, especially when using an LP filter). Once I started going to the dark site, I basically forgot about all the data I had acquired for the Pleiades.

With it's recent rediscovery, including matching flat frames, I decided to reprocess with my more advanced PixInsight skills. I used SubframeSelector to cull out the worst of the subs, and I ended up with just over 9 hours of data in the new integration, produced entirely with PixInsight using better master bias and master dark frames, as well as some additional cosmetic correction to fix hot and cold pixels that the darks missed (my darks were similar in temp, but newer, and not all of the hot and cold pixels matched). I then processed the resulting integration entirely in PixInsight.





The Pleiades - 9Hr+ - Canon 5D III, 150s @ ISO 400 | PixInsight (linear & non-linear)





This data was actually one of the few that I acquired unfiltered from my back yard. All but a couple other images were acquired with the Astronomik CLS, which greatly enhanced emission nebula, but was not very good for broadband objects like Pleiades or Andromeda Galaxy. I was a bit surprised when the final integration revealed some of the faint reddish-brown dust that exists in the space behind the Pleiades...such a detail is usually reserved for dark sites. The overall detail is not as good as my current work, as my tracking back in those days was not as good as it is these days...however it turned out pretty good for what it is, and for how much data spanning such a broad range of time was stacked.


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## Maximilian (Apr 20, 2016)

jrista said:


> ... Back then, I was still just a beginner, and my skill ...
> [snip]
> ... The overall detail is not as good as my current work, as my tracking back in those days was not as good as it is these days...however it turned out pretty good for what it is, and for how much data spanning such a broad range of time was stacked.


Jon, seeing your pictures - no matter if they're from your "beginner" time or else - I sometimes wish I had even more passion for Astronomy and astro photography than I already have and do this myself. 
It is really great work that I see here and I thank you for sharing this with us. 

I know that except from some nights of visual observations with my 6" I won't go further on this because of my two sons and me being "early birds" and a night without sleep causes to much sulky day afterwards.

So once again, you for sharing.


----------



## jrista (Apr 20, 2016)

Maximilian said:


> jrista said:
> 
> 
> > ... Back then, I was still just a beginner, and my skill ...
> ...



Thank you, Max. 

If you are interested in this stuff, and you have a 6" reflector, you might want to give planetary imaging a try. Lot less demanding, cheaper equipment, easier to get rolling. You need good seeing to get hte best results, but imaging Jupiter can be done in a couple of hours total, from setting up to processing the data, while DSO imaging can often take days to get through the whole process.


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## Maximilian (Apr 21, 2016)

jrista said:


> Thank you, Max.
> 
> If you are interested in this stuff, and you have a 6" reflector, you might want to give planetary imaging a try. Lot less demanding, cheaper equipment, easier to get rolling. You need good seeing to get hte best results, but imaging Jupiter can be done in a couple of hours total, from setting up to processing the data, while DSO imaging can often take days to get through the whole process.


Thank you for encouraging me.

In my backyard there is a lot of light pollution from street lights and also some high trees. 
The latter isn't that dramatic as you just have to concentrate away from the light polluted horizon. 
But if you want to have really good seeing (5mag and better) in Germany you'll have to drive a few meters to find field or enclosure where it's dark enough.
But I was able to show my sons Jupiter lately from my backyard and I was positively surprised how well I could see the bands in the atmosphere and we were lucky that all four Galilean moons were in perfect position to be observed. So maybe seeing is better than I think


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## telemaq76 (May 7, 2016)

New picture of M81+M82
24* 5 minutes with canon 700d astrodon+500f4+tc 1.4III+neq6pro
+ dof
Iris and bit of photoshop


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## Click (May 7, 2016)

That's a very nice shot. Well done, telemaq76.


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## rpt (May 7, 2016)

Click said:


> That's a very nice shot. Well done, telemaq76.


+1
Excellent! Thanks for sharing.


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## rfdesigner (May 7, 2016)

telemaq76 said:


> New picture of M81+M82
> 24* 5 minutes with canon 700d astrodon+500f4+tc 1.4III+neq6pro
> + dof
> Iris and bit of photoshop



Thanks for sharing. Nicely done and a decently flat background, unusual to see another user of IRIS, I thought I was one of the last to still use it.


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## jrista (May 8, 2016)

Very nice work, Telemaq. Very nice indeed. I am pretty amazed you were able to bring out that detail with IRIS...not many IRIS users out there.


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## telemaq76 (May 8, 2016)

thank you guys i appreciate. I enjoy m16, m17, m8 back soon 

i ve a question for people shooting with a dslr...do you shoot all your pictures with 1 seconde delay or do you wait a delay , 15 or 30 secondes between each pictures...to let the sensor cool down a bit? is it necessary to do that? i always shoot no stop with 1 sec delay but i wonder if it s better to wait between each shot


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## rfdesigner (May 8, 2016)

telemaq76 said:


> thank you guys i appreciate. I enjoy m16, m17, m8 back soon
> 
> i ve a question for people shooting with a dslr...do you shoot all your pictures with 1 seconde delay or do you wait a delay , 15 or 30 secondes between each pictures...to let the sensor cool down a bit? is it necessary to do that? i always shoot no stop with 1 sec delay but i wonder if it s better to wait between each shot



I would doubt it's going to make much difference, the ability for the sensor to cool down is unlikely to make much difference unless you're throwing away 50% or more of your imaging time, I never waited when I was using DSLR. I just accepted the dark current would change and compensate in calibration.
(OPT command)


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## StudentOfLight (May 9, 2016)

My love affair with the Carina Nebula continues...


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## rfdesigner (May 9, 2016)

StudentOfLight said:


> My love affair with the Carina Nebula continues...



nice!.. faint nebulosity is really starting to show through.

are you still on ~2s exposures?

Edit: I think this is good enough to start thinking about how to scale the image without clipping stars, I've done this by just scaling the luminance and also by isolating the stars and the nebula into two images then processing them and joining them back together at the end. The final effect is to have lots of stars with somewhat accurate colours rather than having them all comming out white. Point is, there's more than just one way to do it, so I don't want to tell you this way or that way is what you need to do, just wanted to hi-light another step to make the image even better.

here's an example where no stars are clipped, it still needs a lot more data as the Galaxy is hidden behind dust in the milky way, but it will do to show how even the very brightest stars are not clipped:


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## StudentOfLight (May 10, 2016)

Thanks again for the feedback. I'll definitely implement the highlight retention processing going forward. 

Side-note: On this occasion humidity was about 72% as well so not very good seeing conditions.

I'm still unfortunately without a tracking mount so there is still a tiny bit of trailing in my stars. So perhaps you guys can offer some advice. I think these are my requirements:
0) I'm looking to spend $800-1600 on a mount + drive system
1) I'm currently using the 6D, but will likely get an 80D (or 7D-III) in the future
2) I'm most interested in shooting objects with lenses in the 70-400mm focal length range
3) I value portability as I'd want to drive to a remote location and hike still further away from roads
4) I might get a telescope at a later stage so focal length could become a bit longer
5) I'd be happy with getting reasonably accurate tracking for 2-3 minute sub-exposures (Is that a realistic expectation given my price range?)

Ideally I'd want to walk into a brick-and-mortar shop, see the products first-hand, and speak in-person to an expert, but I don't think there are many shops like this anymore, not where I live at least.


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## rfdesigner (May 10, 2016)

StudentOfLight said:


> Thanks again for the feedback. I'll definitely implement the highlight retention processing going forward.
> 
> Side-note: On this occasion humidity was about 72% as well so not very good seeing conditions.
> 
> ...



First you should be aware of your image scale. 400mm on a 6D is about 3.3arc seconds per pixel, if your mount is thrashing by 60 arc seconds peak to peak due to drive imperfections then you'ld need to autoguide that out or reduce focal length. The most major of these imperfections is called Periodic Error (PE). 

Assuming 60 arc seconds peak to peak periodic error (not at all uncommon in more affordable mounts), up to 20mm focal length will not need guiding regardless of shot length. If your PE period is say 4 minutes (time), then you could go to 40mm with roughly 1 minute shots as you won't suffer the whole magnitude of the PE just a portion so it shoudn't show. You could go to 80mm with 30 second shots and so on. A 30 arc second PE would double all the focal lengths without needing to guide.

If you end up adding guiding (second scope/lens or off-axis guider and a guide camera) + laptop to control the whole thing and to tether the camera, then the lower the periodic error the less there is to have to correct and the less overall error you'll get in your images. Remember a guide setup will only correct for errors THAT HAVE ALREADY OCCURRED and so are in your final exposure.

When it comes to mounts you want:

A: solid (so it doesn't flex at the first breath of wind) = expensive
B: accurate tracking. (so the stars stay in position) = expensive

Clearly something that's too heavy to lift is no good as a portable mount, but I don't think you're in that price range.

Here is a list of many available mounts all tested for periodic error. Some mounts allow you to correct for the average periodic error of the mount, but that still leaves a significant random element, and again the lower the uncorrected PE the better the final result.

http://lambermont.dyndns.org/astro/pe.html

Don't spend cash on a better camera for the sake of astrophotography at this stage, spend it on a mount and then in time, on a guiding setup. If you want a new camera for other reasons, by all means buy another camera.

AFTER that you might concider a dedicated cooled astro CCD or an IR modified DSLR.

Most shops are very thinly spread, but the vast majority will be only too willing to help and a few phone calls will help to put you on the right track, but do phone around. I will also point you at places like http://www.cloudynights.com and http://www.stargazerslounge.com Both generally good sites with many helpful posters, the second is mainly UK based.


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## StudentOfLight (May 11, 2016)

I will be going to a public talkby Dr Lucia Marchetti at the Astronomical Society on Saturday evening so will hopefully meet some local astrophotographers who could perhaps advise regarding local suppliers or perhaps second-hand equipment which would meet my requirements. But it definitely helps to have some background knowledge regarding what to look out for, so the advice is much appreciated.


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## StudentOfLight (Jun 19, 2016)

Sprained my foot so wasn't able to get out to a good dark sky area this past dark cycle. I shot this in my back yard... Mars and Saturn in Scorpius. Hopefully the weather will clear up and I'll have a good go at a better dark sky area and hopefully with low humidity as well.


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## rpt (Jun 19, 2016)

StudentOfLight said:


> Sprained my foot so wasn't able to get out to a good dark sky area this past dark cycle. I shot this in my back yard... Mars and Saturn in Scorpius. Hopefully the weather will clear up and I'll have a good go at a better dark sky area and hopefully with low humidity as well.


Sorry to hear that. Hope it heals fast.


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## alexthegreek (Jun 25, 2016)

Greetings creatures of the night!I was just wondering if anyone has used a pentax with that sensor shift resolution thing for astro stuff.Would it even be possible (given that tracking is good enough) ?I would have started a new thread but believe it or not I don't know how to!


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## rfdesigner (Jun 25, 2016)

alexthegreek said:


> Greetings creatures of the night!I was just wondering if anyone has used a pentax with that sensor shift resolution thing for astro stuff.Would it even be possible (given that tracking is good enough) ?I would have started a new thread but believe it or not I don't know how to!



check if the camera can work without a lens (i.e. with a telescope) if you get the bug big time you will want to upgrade to that way of doing things and changing systems is a right royal pain.

This is one of the reasons Canons do well for astro.




StudentOfLight said:


> Sprained my foot so wasn't able to get out to a good dark sky area this past dark cycle. I shot this in my back yard... Mars and Saturn in Scorpius. Hopefully the weather will clear up and I'll have a good go at a better dark sky area and hopefully with low humidity as well.



nicely done, your astro skills are certainly getting better.


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## jrista (Jun 30, 2016)

alexthegreek said:


> Greetings creatures of the night!I was just wondering if anyone has used a pentax with that sensor shift resolution thing for astro stuff.Would it even be possible (given that tracking is good enough) ?I would have started a new thread but believe it or not I don't know how to!



The sensor shift thing will occur over a short period of time, which probably would not work in an astro context. You need very long exposures for astrophotography, and a jittery sensor is actually going to cost you resolution, rather than improve it. I would avoid any camera that uses in-body image stabilization, or sensor shifting for increased resolution, etc. You need as much stability and rigidity as you can get with astrophotography.


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## East Wind Photography (Jun 30, 2016)

If the weather holds this weekend, i'll be testing the long exposure capability of the 1dx2. Anyone used it yet for astro and have any comparisons with some of the predecessors? The weight is a concern for me but if results are good its an excuse to buy a larger/better mount.


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## East Wind Photography (Jul 3, 2016)

So far im pretty impressed with the 1dx2. I shot a few series of three different objects at iso 3200 since with the 5d3 1600 seemed to be the sweet spot. I still have a lot of processing to do so stay tuned. 

Jrista, i need some help though on getting good flats. Ive tried a gazillion different things and its just not working the way i expect it should. Do they need to be at the same iso and shutter speed or is the same aperture good enough? I finally tried using the blue sky this morning but final results are still vignetted and pretty severly. Iso and shutter were different but aperture was the same.


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## East Wind Photography (Jul 3, 2016)

Oh one thing i noticed anout the 1dx2, in live view there is no shutter to start the exposure. It just starts. With my other bodies there is some mechanics still to get things going. I heard some talk about canon using a circular shutter in this model. Even in ttl mode, the shutter actuation has much less effect on the stars. In fact it had no effect in my testing.

Im wondering if the new shutter mechanism exerts a zero intertia. That is the same amount of force in all directions instead of left to right or right to left? Even with the mirror flop it seemed more stable.

More testing is required but so far i see some big plusses from the mechanical aspect.


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## telemaq76 (Jul 4, 2016)

East Wind Photography said:


> Oh one thing i noticed anout the 1dx2, in live view there is no shutter to start the exposure. It just starts.



same with the 1dx MK1, in liveview it just starts, which is good , no vibration . But image is so bad compared to my 300$ canon 700d modified astrodon with cls filter. I m not sure a 1dx2 is the best tool for astrophotography. I m sure you can do much better with a small body mofidied and much much much better if you have money with a ccd camera


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## East Wind Photography (Jul 4, 2016)

telemaq76 said:


> East Wind Photography said:
> 
> 
> > Oh one thing i noticed anout the 1dx2, in live view there is no shutter to start the exposure. It just starts.
> ...



Oh, no, there are better options for Astro. however the 1dx2 brings in the money so it's what I have. I haven't seen anyone using one for astro yet so thought I'd give it a shot. The rain has kept me indoors for months so happy to get out and give it a shot.


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## East Wind Photography (Jul 4, 2016)

Here is a stack I did with the 1dx2, 59 subs, 45 seconds, ISO 3200, 300mm F2.8L IS II. I stacked them in DSS and unfortunately have my crappy laptop with me that only has Canons DPP for editing.  I was surprised that it let me edit a TIFF image. Still it has it's limitations for this purpose. Sorry the colors are off. Need to profile this laptop it seems.


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## telemaq76 (Jul 7, 2016)

finally a night without clouds, first one for monthes...and here is my first test on this object, ngc 6990





26 pictures 2min30 +dof
canon 700da+500 f4 is+neq6pro
Iris then photoshop


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## Click (Jul 7, 2016)

Great picture, telemaq76.


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## lion rock (Jul 7, 2016)

Wow, great shot!
I feel like going out there to visit.
-r



telemaq76 said:


> finally a night without clouds, first one for monthes...and here is my first test on this object, ngc 6990
> 
> 
> 26 pictures 2min30 +dof
> ...


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## telemaq76 (Jul 7, 2016)

thanks you guys a new one, same region of the sky more wide angle, 200mm on my canon 700da
17 x 4min30 +dof


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## StudentOfLight (Jul 8, 2016)

Got a couple of hours of good conditions tonight before humidity started building up. Just enough time to test out my new 35mm. Here is a corner comparison between the 35L II and the 24L II at f/1.4. I'm absolutely blown away by this new lens. :'( Tears of joy I tell you! The slight astigmatism is only in the extreme corners. I can't believe how usable the f/1.4 performance is for astro.

p.s. The Omega Centauri globular cluster is in corner of the 35L II image.


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## telemaq76 (Jul 8, 2016)

yes the 24 1.4 II is pretty "not great" in the corner. new generations lens are far better. My new tamron 15-30 2.8 is almost perfect compare to 24 1.4 II too. 

Here is another shot i took last night, was just a try, few minutes before the end of the night. Just time for 5 exposures of 4min30, blended in photoshop, no dof. But the night was really clear and the result is already interesting then i keep and publish it.


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## StudentOfLight (Jul 8, 2016)

telemaq76 said:


> yes the 24 1.4 II is pretty "not great" in the corner. new generations lens are far better. My new tamron 15-30 2.8 is almost perfect compare to 24 1.4 II too.
> 
> Here is another shot i took last night, was just a try, few minutes before the end of the night. Just time for 5 exposures of 4min30, blended in photoshop, no dof. But the night was really clear and the result is already interesting then i keep and publish it.


There are some deep sky objects that are just too far North for me to shoot. This is one which only rises about 8 degrees above the horizon for me. Another great image!


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## StudentOfLight (Jul 10, 2016)

The Prancing Horse nebula, Rho Ophi Molecular Cloud Complex, and Great Bulge. 
Total Exposure: 22x 8.0s @ f/1.4, ISO 1600

I'm loving the new 35L lens if Canon releases a similar 135L update I'll be over the moon.

DSS has been driving me mad. It failed 7 times trying to stack approx 240 light images, every time with a different issue. With great frustration I just ended up stacking 22 tif files with with a manual vignette guestimate, so no proper calibration. I'll try and find out what is going wrong when I've gotten some sleep and have a fresh mind. 

Anyway, there is such a wealth of deep sky objects in this region of the Milky way. I hope the next month or so I'll have clear skies again and get a chance to zoom in and get some good quality exposures with more pixels on target.


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## rfdesigner (Jul 11, 2016)

StudentOfLight said:


> The Prancing Horse nebula, Rho Ophi Molecular Cloud Complex, and Great Bulge.
> Total Exposure: 22x 8.0s @ f/1.4, ISO 1600
> 
> I'm loving the new 35L lens if Canon releases a similar 135L update I'll be over the moon.
> ...



I love the results you're getting... your processing is improving nicely.


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## jrista (Jul 11, 2016)

StudentOfLight said:


> The Prancing Horse nebula, Rho Ophi Molecular Cloud Complex, and Great Bulge.
> Total Exposure: 22x 8.0s @ f/1.4, ISO 1600
> 
> I'm loving the new 35L lens if Canon releases a similar 135L update I'll be over the moon.
> ...



Nice work! That's a great FoV. 

DSS does have a good number of bugs, and it crashed frequently with me as well. That was one of my primary motivations for moving to PixInsight, which allows me to successfully integrate thousands of frames if I need to. It is not free, but it is WELL worth the cost, IMO.

Quick note. The green cast in your image? You can eliminate that with HLVG, or Hasta La Vista Green, a plugin for Photoshop. Or, you can use the SCNR tool in PixInsight. Either will do just fine, and once the green cast is gone, your image will have much better color calibration.


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## StudentOfLight (Jul 12, 2016)

Thanks RFD & Jrista.

That green cast was quite bad and the clarity is also very harsh. My laptop screen is not calibrated... so now that I've gotten to process with my desktop, the colors should be more accurate.

Here is the updated image. I selected the 100 best frames and stacked them using 3x drizzle on portions of frame using 12 portions. I then Stitched the resulting 12 images into a single image and finally cropped in to get roughly 85MP for the final image. (I scaled down for web use)


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## telemaq76 (Jul 12, 2016)

nice, new edition far better


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## telemaq76 (Jul 12, 2016)

classic laguna view. not enough time between clouds again, only 6 exposure 150 seconds, blended in photoshop


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## Click (Jul 12, 2016)

telemaq76 said:


> classic laguna view. not enough time between clouds again, only 6 exposure 150 seconds, blended in photoshop



Beautiful. Nicely done, telemaq76.


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## telemaq76 (Jul 17, 2016)

the dumbell nebula
only 30x 105 sec + 11dark +flat and offset


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## Click (Jul 17, 2016)

Very nice shot. Well done telemaq76.


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## telemaq76 (Jul 17, 2016)

thanks click, just done this morning with moon 88%, ngc7000. Half time was done at night end ,with moon very low on horizon
41 light 165 sec, 28 dark, 15 flats, 100 offset


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## Click (Jul 17, 2016)

Awesome. Very impressive picture.


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## StudentOfLight (Jul 17, 2016)

telemaq76 said:


> thanks click, just done this morning with moon 88%, ngc7000. Half time was done at night end ,with moon very low on horizon
> 41 light 165 sec, 28 dark, 15 flats, 100 offset


Wow, the depth is great.


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## telemaq76 (Jul 24, 2016)

thank you for feedback, here is the same ngc7000 with 500mm
finally a long night with no clouds. not great with the 85%moon but better than nothing


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## Click (Jul 24, 2016)

Stunning picture. Well done, telemaq76.


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## telemaq76 (Aug 2, 2016)

new target, ic1318, 32x270 sec +dof


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## Click (Aug 2, 2016)

Very impressive. Great shot. Well done, telemaq76.


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## rpt (Aug 2, 2016)

Click said:


> Very impressive. Great shot. Well done, telemaq76.


+1

Lovely shots telemaq76! 

I have no hope for the next month or two. The monsoons are in full swing. I will attempt in October.


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## StudentOfLight (Aug 3, 2016)

Here is my first stack of Lagoon and Trifid:



Lagoon &amp; Trifid by Omesh Singh, on Flickr


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## StudentOfLight (Aug 4, 2016)

Here is a wide-field shot of Scorpius Constellation including Rho Ophi Molecular cloud. I struggled a bit with my flat and dark-flat frames giving me problems so I stacked without them and manually removed vignette with radial gradient. The color was a bit off though. 

Anyway, I edited to try and give as much color and detail to the molecular gas clouds. I was particularly interested in pulling some detail out of the nebula around Jabbah (IC 4592), which was out-of-frame of my previous wide-field shot of of the Scorpius region. I also wanted to get good saturation of the reds on the Cat's Paw Nebula:



Wide-Field of Scorpius Constellation by Omesh Singh, on Flickr


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## mtam (Aug 5, 2016)

Belgrade Maine, 10 sec f.18 ISO 1600

This might not show the galaxy far far away. But it adds some depth to the stars. Hope you guys like it.


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## Click (Aug 5, 2016)

mtam said:


> Belgrade Maine, 10 sec f.18 ISO 1600
> 
> This might not show the galaxy far far away. But it adds some depth to the stars. Hope you guys like it.



Yes, I like it. Nicely done.


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## telemaq76 (Aug 7, 2016)

new picture around Sadr
37*270 sec+ dof
canon 700da+cls filter, canon 70-200 2.8 is II @200mm, mount neq6pro


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## Click (Aug 7, 2016)

Awesome. Well done, telemaq76.


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## lion rock (Aug 7, 2016)

Amazing Telemaq! Amazing!
-r


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## mtam (Aug 7, 2016)

@telemaq76

That photo is amazing. Thanks for sharing


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## telemaq76 (Aug 8, 2016)

thank you guys, i admit i think it s my best by far


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## StudentOfLight (Aug 8, 2016)

telemaq76 said:


> new picture around Sadr
> 37*270 sec+ dof
> canon 700da+cls filter, canon 70-200 2.8 is II @200mm, mount neq6pro


Another great image.

What is dof?


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## jrista (Aug 10, 2016)

Telemaq, that image is excellent! I really love the HUGE field of view. Well done!


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## Don Haines (Aug 11, 2016)

telemaq76 said:


> new picture around Sadr
> 37*270 sec+ dof
> canon 700da+cls filter, canon 70-200 2.8 is II @200mm, mount neq6pro



All I can say WOW!, WOW!!, and WOW!!!


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## telemaq76 (Aug 12, 2016)

StudentOfLight said:


> telemaq76 said:
> 
> 
> > new picture around Sadr
> ...



DOf ..Dark, Offset, Flat  DOF


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## scyrene (Aug 12, 2016)

telemaq76 said:


> new picture around Sadr
> 37*270 sec+ dof
> canon 700da+cls filter, canon 70-200 2.8 is II @200mm, mount neq6pro



Ooft. One of my favourite patches of sky, and a truly excellent rendition.

I just got a new telescope and mount, hoping to get some shots of my own as soon as the clouds give me a break (as if).


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## StudentOfLight (Aug 14, 2016)

telemaq76 said:


> StudentOfLight said:
> 
> 
> > telemaq76 said:
> ...


Thanks. I knew there was some good explanation.

Interestingly here in South African one of our languages is Afrikaans, and the word "dof" means dull or if you refer to a person as being "dof" you mean that they are dimwitted. So I was feeling "dof" trying to figure out what you meant by "dof" LOL ;D


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## Mickat (Aug 15, 2016)

I'm a little jealous of the images that everyone is posting up. Some great work.

I hope to be able to do some astro imaging soon with my 11" EdgeHD scope soon, I've just ordered an attachment for the secondary mirror to be removed and mount my camera to the front for some nice F2 imaging. Hopefully i'll be able to post some stuff up soon.


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## jrista (Aug 17, 2016)

I have not had much clear sky time this year. Been extra heavy on the clouds. Originally that was because of El Ninio, which was hot and heavy until the end of spring this year. But, the pacific conditions are returning to La Ninia status...so, I honestly don't know why the clouds are still perpetual. 

Anyway...I dropped $3700 on some new camera gear in April. I've only been able to use it once...on the moon!  Just to give you guys an idea of how much better dedicated astro gear can be...this is from an ASI1600MM-Cool camera, running at -15°C. I used very high quality AstroDon LRGB filters (these alone cost $500), since the camera is monochrome. The camera has only 1.5e- read noise, and 0.008e-/s dark current @ -15C (compared to my 5D III, which has a monstrous 4e-/s @ 28C!!!) So, this is an ultra low noise camera. 

I acquired high speed video sequences for four filters, LRGB, between 30-50fps. Graded, culled, aligned and stacked the top 15% of those in a program called AutoStakkert!2 to get individual Luminance (L), Red, Green and Blue channel images. I then processed those in PixInsight to combine it all into a deconvolved, high detail full-color image:







You can see a larger version here:
http://www.astrobin.com/full/260298/B/

And, for those who are willing to download the full size, you can see that here:
http://www.astrobin.com/full/260298/B/?real=&mod=


To contrast the quality of this camera with what I've been able to get with my 5D III. This is the largest lunar image I've had with the 5D III:






See full size here: http://i.imgur.com/NiWu0FV.jpg

I used video capture with this one, but the 5D III can barely sustain about 20fps. On top of that, the low pass filter and interpolation to convert the bayer CFA to a full color image really softens things up. The next highest resolution single-image of the moon I've got from the 5D III is this guy:






See full size here: http://i.imgur.com/r7DlVOz.jpg

This was a while ago, but it was on a night of very good seeing, so the detail was pretty darn good. But it only holds up at this size...again, the low pass filter and interpolation soften things up. The ASI1600 has neither a low pass filter, nor does it need to be demosaiced...you get a 100% fill factor on every channel.


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## Click (Aug 18, 2016)

Great pictures, Jon. 

Congrats on your new equipment.


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## telemaq76 (Aug 18, 2016)

i never seen picture of the moon that shap, incredible details. can you image deep sky with that camera or only planet?


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## telemaq76 (Aug 18, 2016)

i bought only h-alpha filter , it was boring to see perfect sky only full moon days, then now i can shoot even with it s heavy moon in the sky. My first try on nc7000 with 85, 200 and 500mm .


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## jrista (Aug 18, 2016)

Thanks Click, Telemaq!

Telemaq, the pixels on this camera are 3.8 microns. Very small! Combined with a high resolution telescope (AstroTech 8" Ritchey-Cretien), it gave me an image scale of 0.482"/pixel. The diffraction limited resolution of the scope is 0.57". The seeing on these nights was between 0.5-0.6". So, I was basically working at the diffraction limit, and seeing was not blurring things as much as it usually does (actually, 0.5" seeing is...phenomenal!)

I kind of made out like a bandit on the resolution.  It's pretty rare that the celestial forces align and give you clear skies, transparent skies, and skies with good seeing all at once. To be able to image diffraction limited is like bliss!  I suspect I won't get another chance like this any time soon. 

Your narrow band images look great! I'm curious though...what camera was that? Is it astro-modded, full-spectrum modded, or mono modded?


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## meywd (Aug 18, 2016)

Amazing pictures Jon, and congratulations on the new gear.


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## meywd (Aug 18, 2016)

telemaq76 said:


> i bought only h-alpha filter , it was boring to see perfect sky only full moon days, then now i can shoot even with it s heavy moon in the sky. My first try on nc7000 with 85, 200 and 500mm .



Beautiful photos, thanks for sharing


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## meywd (Aug 18, 2016)

Largest Orion Nebula Image taken with the VLT


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## Click (Aug 18, 2016)

Beautiful shot, meywd. Well done.


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## meywd (Aug 18, 2016)

Click said:


> Beautiful shot, meywd. Well done.



This is not mine click, I wish it was ;D, this was taken by the Very Large Telescope in chili, and remastered by an Astro photographer, you can see the details in the link below the image


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## Click (Aug 18, 2016)

Oops! ;D I didn't notice the link, I thought it was yours. It's a stunning picture. Thanks for the info.


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## StudentOfLight (Aug 18, 2016)

jrista said:


> I have not had much clear sky time this year. Been extra heavy on the clouds. Originally that was because of El Ninio, which was hot and heavy until the end of spring this year. But, the pacific conditions are returning to La Ninia status...so, I honestly don't know why the clouds are still perpetual.
> 
> Anyway...I dropped $3700 on some new camera gear in April. I've only been able to use it once...on the moon!  Just to give you guys an idea of how much better dedicated astro gear can be...this is from an ASI1600MM-Cool camera, running at -15°C. I used very high quality AstroDon LRGB filters (these alone cost $500), since the camera is monochrome. The camera has only 1.5e- read noise, and 0.008e-/s dark current @ -15C (compared to my 5D III, which has a monstrous 4e-/s @ 28C!!!) So, this is an ultra low noise camera.
> 
> ...


How much of a difference do you think the 5D-III's AA-filter is having? 

I've also been wondering lately... does a lack of AA-filter results in better SNR?


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## telemaq76 (Aug 18, 2016)

The bubble nebula. pretty wide field even with a 500mm on apsc sensor





69x150 sec exposures
25 darks
1000 offsets
15 flats
camera : canon 700da+filtre cls-ccs
lens : canon 500 f4 is
mount skywatcher neq6pro


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## telemaq76 (Aug 18, 2016)

jrista said:


> Your narrow band images look great! I'm curious though...what camera was that? Is it astro-modded, full-spectrum modded, or mono modded?



it s a small 300$ used canon 700d, modified astrodon. and i used the eos-clip h-alpha filter , the best one, the 6nm a++. the filter costs same price that the camera !


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## jrista (Aug 18, 2016)

telemaq76 said:


> jrista said:
> 
> 
> > Your narrow band images look great! I'm curious though...what camera was that? Is it astro-modded, full-spectrum modded, or mono modded?
> ...



Yeah, good quality narrow band filters are not cheap. Earlier this year, I was considering getting one of the new KAF-16200 cameras, with APS-H size sensors. The necessary filters for that were the 2" or 50mm square. Those suckers cost $1200, EACH!  Just to get a full set of narrow band filters, I would have had to spend $3600, and that was on top of the camera price of $7000, and the filter wheel price of about $2800. 

The insane cost of all of that was one of the reasons I went with the ASI1600 instead. It is a smaller sensor, but it was far cheaper overall. I managed to get a full set of NB filters, and the LRGB filters, and the filter wheel, camera, and all the necessary adapters for a little over $3700.


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## jrista (Aug 18, 2016)

StudentOfLight said:


> How much of a difference do you think the 5D-III's AA-filter is having?
> 
> I've also been wondering lately... does a lack of AA-filter results in better SNR?



The AA filter has a huge impact. With the AA filter, I can't really get stars less than about 4.2" in size (FWHM, full width half maximum, as we call it) most of the time. In the absolute best of conditions, my stars get down to about 3" with the 5D III...but, that is very rarely, and I don't think it can really get much better than that. 

The diffraction limited performance of my 600mm lens is 0.76", and the diffraction limited performance of my AT8RC is 0.48". So, even a 3" star is 4x larger than my 600mm lens is capable of, and over 6x larger than the RC is capable of. However, with the ASI1600, I've had my stars down around 1.5" pretty often. Smaller pixels, but also no low pass filter. The low pass filters really blur the crap out of things, no question. 

For astrophotography, you don't have any patterns that can create moire. Even if you image undersampled, you can recover detail and smoothness by drizzling, which will recover lost resolution. So, cameras that don't have a low pass filter will usually produce better results. 

As for SNR. Yes, sharper details will have better SNR. If a filamentary structure is really 5" in size, but is being blurred to 10" in size, then all the signal information that should have been concentrated in half the area, is being spread out over twice the area. And, for any given unit area, the SNR will be lower when the information is blurred. So a low pass filter can definitely hurt your SNR. Same thing goes for not having ideal focus. If your focus is off, your blurring information, spreading the photons out over a greater area. The total signal coming from the object at large is the same, but the focused signal for specific parts of the object can be reduced (because they are being redistributed over a larger area.)


----------



## scyrene (Aug 19, 2016)

jrista said:


> StudentOfLight said:
> 
> 
> > How much of a difference do you think the 5D-III's AA-filter is having?
> ...



Hi Jon. Thanks for the Flickr favourite on my cuckoo (I guess that was you!). I just got a modest telescope (4SE) and have been fiddling around with my DSLR as a webcam for planetary imaging using the telescope and using the tracking mount with a lens for deep sky stuff, but of course have been looking at how to improve things. So two questions...

With regards to planetary things, is a basic astro webcam better than the 5Ds? I've rigged it up using the Canon software and QuickTime to record the magnified LiveView feed directly on my computer - which works but is awkward. As for deep sky, is a dedicated astro cam better? Given it's such a cheap telescope and mount, would I be better off investing in filters? (I live in a moderately light polluted place). I saw it's possible to mount a deep sky CCD directly to Canon lenses...


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## jrista (Aug 19, 2016)

If you want to get good results with planetary, you need very high magnification (an SCT with a 2-3x barlow, for around f/20-f/30!!), and you need very high speed video. The idea with planetary is that you use very short exposures with very sensitive cameras (we are talking way more sensitive than any DSLR on the market, 75-85% quantum efficiency) and very low noise (2e- or less, many planetary cams have less than 1e- read noise!) so that you can get exposures that are on the time-order of scintillation. Scintillation is the word used to describe the main form of high-frequency high altitude turbulence or "seeing" that affects planetary imaging. Scintillation is caused by the jetstream. 

At a frame rate of 100fps or more, your exposure lengths are 10ms or shorter, which is around the time-order of scintillation. There are larger-scale effects from seeing that occur over longer time periods...around a second or so, and larger around 10-30 seconds. With a DSLR, especially a high resolution one, in a high quality video mode, you are usually lucky to get 30fps...with the 5D III I can only get about 20fps sustained at full resolution. You also cannot choose an ROI (region of interest) with a DSLR, so your stuck reading the entire sensor out at full resolution, when most of the time for planetary you just need a tiny 400x400 pixel or smaller ROI. 

DSLR video also entails all the read noise the camera can pump out, which can be rather extreme when in high speed video, because the sensor heats up, which jacks the dark current level up, which introduces even more noise on top of the base read noise (which, BTW, is higher with a higher speed video readout than a standard single frame readout.) Finally, the video coming out of a Canon DSLR is usually compressed, which is less than ideal for planetary imaging. 

A dedicated planetary camera (I'd look at ZWO, their ASI camera line, particularly the new USB 3 products like the 224MC or 178MM) is going to be extremely low noise, extremely high sensitivity, capable of delivering hundreds of frames per second with ROI's down to 100x100 pixels, and with hardware binning on a mono camera, your frame rates can get upwards of 300fps to nearly 800fps (good for solar and lunar imaging). There is little comparison between a dedicated planetary camera, and a DSLR, these days. 

The ZWO ASI178MM for example, is an excellent planetary cam. It has as little as 1.4e- read noise, uses a Sony BSI sensor, quantum efficiency is up around 80%, frame rates up to 240fps unbinned (480fps binned!), and it's 14-bit so the IQ is very high quality. It's a monochrome camera (although i think there is also a color version), so you can use LRGB filters with it to get the maximum quality (and ZWO just released a really nice mini filter wheel that supports 1.25" filters, and they sell an LRGB filter set themselves as well).

https://astronomy-imaging-camera.com/products/usb-3-0/asi178mm-mono/
https://astronomy-imaging-camera.com/products/accessories/efw-mini/
https://astronomy-imaging-camera.com/products/accessories/zwo-new-rgbl-filters-optimised-asi1600/
https://astronomy-imaging-camera.com/products/usb-3-0/178mm-kit/ (NOTE: This kit uses the manual filter wheel, not the new EFW-mini linked above! An electronic filter wheel is very handy...but, it does require a laptop or other computer to be connected, and software that supports filter wheel control to be used.)

The difference in planetary, lunar and solar imaging with the ASI178MM would be orders of magnitude better than imaging with a 5Ds. Absolutely no comparison. These cameras are also very small, very light weight, low power, so they are highly portable and easy to haul around to dark sites if you want. While the sensors are small, they can also be used to do longer exposure astrophotography, and with a mono camera with LRGB sensors, you'ed smoke the 5Ds for small FoV imaging (i.e. galaxies, or close up imaging of nebula details). 

The 5DsR would make a great wide field camera, though. The 178 cant come close to delivering the kind of huge full frame field of view that the 5DsR could, and the R, lacking a low pass filter, would deliver great image quality. The difficulty there, actually, is getting a large enough image circle. Canon lenses certainly have them, but few are actually good for astrophotography. Most regular refracting telescoeps, and for that matter some of the lower end reflecting telescopes, just don't have a large enough image circle for a full frame sensor. That is one of the reasons I use my 600mm lens as a telescope...it's got a very large image circle.

As for light pollution. Imaging with a monochrome camera is far more efficient than imaging with a color DSLR. Note how I've said LRGB. That stands for Luminance, Red, Green, Blue. If you just used RGB filters, while you would be more efficient at gathering light than a color DSLR, it is really the L filter that sucks down the photons. An L filter is a full spectrum filter, square cutoff, blocking UV and IR, but otherwise passing the entire visible spectrum with over 95% transmission. The red, green and blue color filters in a bayer sensor are not even square bandpasses, they are more along the lines of a gaussian bandpass, and their transmission levels are usually not even 90%. So, combine L imaging, with RGB imaging. You can acquire photons far, far faster by getting lots and lots of L subs, and just enough RGB subs to avoid issues with noise and stack properly (usually about an hour to an hour and a half for each RGB channel, then all the rest of your time on the L channel).

So if you want to do full color imaging in the city, LRGB with a mono camera is still more efficient than a DSLR (barring FoV differences). The real benefits with a mono camera come from the ability to use narrow band filters, though. With narrow band imaging, you can block out 90% or more of the visible spectrum, and just image one narrow emission band at a time. Hydrogen alpha, Oxygen three, Sulfur two. You need longer exposures, and a many hours of data at least on each channel, but you don't really have to worry about light pollution.


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## telemaq76 (Aug 20, 2016)

my very first h-alpha color image. i mixed an h-alpha picture i just made with a standard picture i ve done weeks ago.



.
It s great i can now shoot with full moon. That s why i bought that h-alpha 6nm filter. Most of the time full moon days are the clearest days of the month, no clouds


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## Click (Aug 20, 2016)

I'm impressed by the quality of your pictures. Well done, telemaq76.


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## scyrene (Aug 23, 2016)

jrista said:


> If you want to get good results with planetary, you need very high magnification (an SCT with a 2-3x barlow, for around f/20-f/30!!), and you need very high speed video. The idea with planetary is that you use very short exposures with very sensitive cameras (we are talking way more sensitive than any DSLR on the market, 75-85% quantum efficiency) and very low noise (2e- or less, many planetary cams have less than 1e- read noise!) so that you can get exposures that are on the time-order of scintillation. Scintillation is the word used to describe the main form of high-frequency high altitude turbulence or "seeing" that affects planetary imaging. Scintillation is caused by the jetstream.
> 
> At a frame rate of 100fps or more, your exposure lengths are 10ms or shorter, which is around the time-order of scintillation. There are larger-scale effects from seeing that occur over longer time periods...around a second or so, and larger around 10-30 seconds. With a DSLR, especially a high resolution one, in a high quality video mode, you are usually lucky to get 30fps...with the 5D III I can only get about 20fps sustained at full resolution. You also cannot choose an ROI (region of interest) with a DSLR, so your stuck reading the entire sensor out at full resolution, when most of the time for planetary you just need a tiny 400x400 pixel or smaller ROI.
> 
> ...



That's fantastic, thanks. Really detailed and concise.

It was wishful thinking of me to hope for a one size fits all approach. I guess it all ultimately boils down to how much money each person thinks it's worth spending... it's so rarely good weather here, I've hesitated to buy much dedicated astro gear. Decisions, decisions...

(At least planetary imaging has the advantage that you don't need such long clear periods, I might start with that, although it's hard to beat the glory of good deep sky images).


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## jrista (Aug 25, 2016)

Yeah, you do need to factor in cost recovery time on your equipment. I purchased the ASI1600, and have only used it twice...once for the lunar image, once already a week ago (more, even) to get some Ha (hydrogen alpha) subs on Cave nebula (and they aren't even keepers due to a tilt issue). I won't be covering much of the cost of the new kit in usage much this year, it seems. However, over the long term...I definitely think it was worth it. It's a pretty amazing camera...incredibly low noise. 

If you only have a handful of days a year to do any astro, then you would want to very carefully weight the options. That said, you can get a full monochrome CMOS kit with LRGB filters with the ASI178MM for about $800. The cost of getting into the mono game has never been so good.


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## scyrene (Aug 25, 2016)

jrista said:


> Yeah, you do need to factor in cost recovery time on your equipment. I purchased the ASI1600, and have only used it twice...once for the lunar image, once already a week ago (more, even) to get some Ha (hydrogen alpha) subs on Cave nebula (and they aren't even keepers due to a tilt issue). I won't be covering much of the cost of the new kit in usage much this year, it seems. However, over the long term...I definitely think it was worth it. It's a pretty amazing camera...incredibly low noise.
> 
> If you only have a handful of days a year to do any astro, then you would want to very carefully weight the options. That said, you can get a full monochrome CMOS kit with LRGB filters with the ASI178MM for about $800. The cost of getting into the mono game has never been so good.



I've looked at that camera and may well get it. It's relatively inexpensive, as you say (and I can always sell it on if I haven't used it in a year or so). Thanks again


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## telemaq76 (Aug 26, 2016)

classic andromeda galaxy





i dont know if it s overprocess?


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## Click (Aug 26, 2016)

Great shot, telemaq76. It's beautiful and not overprocessed. 8)


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## lion rock (Aug 26, 2016)

Beautiful! Need I say more?
-r



telemaq76 said:


> classic andromeda galaxy
> 
> i dont know if it s overprocess?


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## meywd (Aug 26, 2016)

telemaq76 said:


> classic andromeda galaxy
> ...
> i dont know if it s overprocess?



Beautiful telemaq76, not an overprocess, but maybe reduce the tint, more green and less purple.


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## telemaq76 (Aug 27, 2016)

meywd said:


> telemaq76 said:
> 
> 
> > classic andromeda galaxy
> ...



well my first version was too green, i prefer on purple but i ll try on next to find the good balance ...

new picture of ngc 5070 between clouds, sky was not great but pretty happy with the result,was not excpecting that with bad seeing

29x 210 sec exposure f4 iso-800 
dark, flat, offset

Iris and photoshop


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## Click (Aug 27, 2016)

Beautiful picture. Well done, telemaq76.


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## StudentOfLight (Aug 27, 2016)

I like the 3 dimensionality you get with the deeper exposures. 
One day when I'm big...


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## rfdesigner (Aug 27, 2016)

telemaq76 said:


> meywd said:
> 
> 
> > telemaq76 said:
> ...



nice.

if you look VERY closely at the bright wall in the bottom right of the nebula, you can see a dark tendril pointing back to the centre of the nebula. At the tip of this if you zoom in is a bright line across the tenridl, a bit like a bow wave.

If you look this up it's a "Herbig-Haro" object.

https://en.wikipedia.org/wiki/Herbig%E2%80%93Haro_object


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## telemaq76 (Aug 28, 2016)

i tried ic1396,elephant nebula with 500mm with no guiding. not easy, 61 pictures of 210 sec +dark, flat, offset


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## Click (Aug 28, 2016)

telemaq76 said:


> i tried ic1396,elephant nebula with 500mm with no guiding. not easy, 61 pictures of 210 sec +dark, flat, offset




Stunning picture. It's beautiful.


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## scyrene (Aug 28, 2016)

telemaq76 said:


> i tried ic1396,elephant nebula with 500mm with no guiding. not easy, 61 pictures of 210 sec +dark, flat, offset



You're making me jealous with these!


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## StudentOfLight (Aug 29, 2016)

I created a GIF of Scorpion being traced out over my wide-field image from earlier this month.


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## Click (Aug 29, 2016)

StudentOfLight said:


> I created a GIF of Scorpion being traced out over my wide-field image from earlier this month.




Well done.


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## telemaq76 (Sep 2, 2016)

one year with bad weather but this last month was pretty damn good
. i had some good time to shoot this heart nebula
57 x 150 sec +dark, flat, offset
canon 700da+500f4is+neq6pro


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## Click (Sep 2, 2016)

Awesome. It's beautiful. Well done, telemaq76.


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## telemaq76 (Sep 5, 2016)

2 last shoots before rain come back, august month was great for me
Ic11 nebula




and
wizardy nebula


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## Click (Sep 5, 2016)

Beautiful shots, telemaq76. Well done.


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## jrista (Sep 5, 2016)

Telemaq, you have been getting some great results lately! I particularly like your Wizard...floating in space like that, with the almost rainbow palette. Very nice.

While this was not done with a Canon camera, I have been quite amazed at the capabilities of the ASI1600MM-Cool. Once cooled to -20C, there is so little dark current that cooling more deeply doesn't really matter unless you need extremely long exposures. And long exposures can be a pain...so I decided to do the inverse...see what I could do at a high gain with short exposures. This is a mere 1h45m of total integration, 9x90s Ha, 25x90s OIII and 36x90s SII, all from 3nm AstroDon narrow band filters:







These were done at gain 200, which is 0.485e-/ADU, with a bias offset of 50e-. In 16-bit terms, the gain is a massive 0.03e-/ADU!


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## Don Haines (Sep 6, 2016)

telemaq76 said:


> one year with bad weather but this last month was pretty damn good
> . i had some good time to shoot this heart nebula
> 57 x 150 sec +dark, flat, offset
> canon 700da+500f4is+neq6pro





jrista said:


> Telemaq, you have been getting some great results lately! I particularly like your Wizard...floating in space like that, with the almost rainbow palette. Very nice.
> 
> While this was not done with a Canon camera, I have been quite amazed at the capabilities of the ASI1600MM-Cool. Once cooled to -20C, there is so little dark current that cooling more deeply doesn't really matter unless you need extremely long exposures. And long exposures can be a pain...so I decided to do the inverse...see what I could do at a high gain with short exposures. This is a mere 1h45m of total integration, 9x90s Ha, 25x90s OIII and 36x90s SII, all from 3nm AstroDon narrow band filters:
> 
> These were done at gain 200, which is 0.485e-/ADU, with a bias offset of 50e-. In 16-bit terms, the gain is a massive 0.03e-/ADU!



WOW! There are some pretty impressive images getting shown here! You people are an inspiration and I look forward to your next images! Thank you for posting!


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## Don Haines (Sep 6, 2016)

telemaq76 said:


> classic andromeda galaxy
> 
> 
> 
> ...


A beautiful image! How did you do it?


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## telemaq76 (Sep 10, 2016)

The heart nebula
12x240 sec for colors 
44x 240 sec in h-alpha


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## Click (Sep 10, 2016)

Stunning picture. 8) It's beautiful. Well done, telemaq76.


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## alexthegreek (Sep 10, 2016)

Here's my Andromeda galaxy done with my stock 500d (which is about to quit on me, sometimes it doesn't turn on and that will be the end of me) and an old Jupiter 21M 200mm I got for 50 euro.1 min at iso 800 f5.6 about 60 min integration time and about 40-50 (or so I think) darks.Im not sure about the number of darks because deep sky stacker does not seem to be loading the file lists I create with darkmaster correctly.1st group is empty(I've read that's normal), second is ok but the next group is missing a lot of darks!Any idea what's going on?


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## scyrene (Sep 10, 2016)

alexthegreek said:


> Here's my Andromeda galaxy done with my stock 500d (which is about to quit on me, sometimes it doesn't turn on and that will be the end of me) and an old Jupiter 21M 200mm I got for 50 euro.Iso 800 f5.6 about 60 min integration time and about 40-50 (or so I think) darks.Im not sure about the number of darks because deep sky stacker does not seem to be loading the file lists I create with darkmaster correctly.1st group is empty(I've read that's normal), second is ok but the next group is missing a lot of darks!Any idea what's going on?



OOFT. I've been targeting Andromeda recently, but this is so much better than anything I can do! And with modest equipment, well done!


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## alexthegreek (Sep 10, 2016)

scyrene said:


> alexthegreek said:
> 
> 
> > Here's my Andromeda galaxy done with my stock 500d (which is about to quit on me, sometimes it doesn't turn on and that will be the end of me) and an old Jupiter 21M 200mm I got for 50 euro.Iso 800 f5.6 about 60 min integration time and about 40-50 (or so I think) darks.Im not sure about the number of darks because deep sky stacker does not seem to be loading the file lists I create with darkmaster correctly.1st group is empty(I've read that's normal), second is ok but the next group is missing a lot of darks!Any idea what's going on?
> ...



Thanks scyrene!Don't forget this is low res so it makes it look a bit better!


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## scyrene (Sep 10, 2016)

alexthegreek said:


> scyrene said:
> 
> 
> > alexthegreek said:
> ...



Oh I know. But it's still everything I aspire to!


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## Don Haines (Sep 11, 2016)

alexthegreek said:


> Here's my Andromeda galaxy done with my stock 500d (which is about to quit on me, sometimes it doesn't turn on and that will be the end of me) and an old Jupiter 21M 200mm I got for 50 euro.1 min at iso 800 f5.6 about 60 min integration time and about 40-50 (or so I think) darks.Im not sure about the number of darks because deep sky stacker does not seem to be loading the file lists I create with darkmaster correctly.1st group is empty(I've read that's normal), second is ok but the next group is missing a lot of darks!Any idea what's going on?


You people are inspirational!


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## alexthegreek (Sep 11, 2016)

Don Haines said:


> alexthegreek said:
> 
> 
> > Here's my Andromeda galaxy done with my stock 500d (which is about to quit on me, sometimes it doesn't turn on and that will be the end of me) and an old Jupiter 21M 200mm I got for 50 euro.1 min at iso 800 f5.6 about 60 min integration time and about 40-50 (or so I think) darks.Im not sure about the number of darks because deep sky stacker does not seem to be loading the file lists I create with darkmaster correctly.1st group is empty(I've read that's normal), second is ok but the next group is missing a lot of darks!Any idea what's going on?
> ...



Oh man....thanks Don!!


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## BeenThere (Sep 12, 2016)

I was looking at the pixel insight web site and they don't tell you much about how to use the program (beginner). Can anyone recommend some reading/tutorials for getting started with this program?


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## East Wind Photography (Sep 13, 2016)

BeenThere said:


> I was looking at the pixel insight web site and they don't tell you much about how to use the program (beginner). Can anyone recommend some reading/tutorials for getting started with this program?



Best resource is youtube as well as the tutorials on the pixinsight website. It will take you 6 months to a year to master it.


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## jrista (Sep 14, 2016)

telemaq76 said:


> The heart nebula
> 12x240 sec for colors
> 44x 240 sec in h-alpha



Fantastic work, Telemaq!! Seems that H-alpha is helping you here. The contrast is real nice.


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## jrista (Sep 14, 2016)

alexthegreek said:


> Here's my Andromeda galaxy done with my stock 500d (which is about to quit on me, sometimes it doesn't turn on and that will be the end of me) and an old Jupiter 21M 200mm I got for 50 euro.1 min at iso 800 f5.6 about 60 min integration time and about 40-50 (or so I think) darks.Im not sure about the number of darks because deep sky stacker does not seem to be loading the file lists I create with darkmaster correctly.1st group is empty(I've read that's normal), second is ok but the next group is missing a lot of darks!Any idea what's going on?



Great start! Looks pretty good.

Regarding the DSS/Darkmaster issue. I've never used the two together, so I can't say what might be wrong. Any reason you are not just throwing all the files into DSS and letting it do it's thing?


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## jrista (Sep 14, 2016)

BeenThere said:


> I was looking at the pixel insight web site and they don't tell you much about how to use the program (beginner). Can anyone recommend some reading/tutorials for getting started with this program?



PixInsight is phenomenal, truly. Almost all of the images I've shared here on this thread were processed with it. 

You can find quite a lot of tutorials for it online. I've also got some of my own articles covering individual PI tools, and will be adding more if and when I can find the time. Find those here:

https://jonrista.com/the-astrophotographers-guide/pixinsights/


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## jrista (Sep 14, 2016)

I haven't been posting my own images here much lately, as I have not had much clear sky this year. Not much at all. I've also moved on from the 5D III...but, I am still active. I have moved to a monochrome camera with LRGB and narrow band filters. I've had some clear nights finally, and managed to acquire some good data with the new camera. It's not a Canon, so I probably won't be sharing all my images from it here, but here is my latest:

*Wizard Nebula*







All narrow band filters, Ha, SII and OIII. Total integration time is less than 4 hours, which is pretty rare for narrow band images. This new camera is extremely low noise, especially at higher gain. I used gain 200 here, which only has 1.3e- read noise. Dark current is a minuscule 0.006e-/s @ -20C. 

I combined 2 hours of Ha and used that as a "luminance" channel...a monochrome detail channel. The rest was used for color. I combined 24 minutes of Ha, 40.5 minutes of OIII and 52.5 minutes of SII to create individual narrow band channels. Those were combined into RGB via a custom 'PixelMath' blend in PixInsight:


```
RED: (SII*.8 + Ha*.2)*.45 + (Ha*.8 + OIII*.2)*.55
GREEN: (Ha*.3 + OIII*.7)*.45 + (Ha*.2 + OIII*.7)*.55
 BLUE: OIII
```

This effectively blends two different "standard" blends together to make a custom blend. The first standard blend is SHO, or Sulfur/Hydrogen/Oxygen mapped to Red/Green/Blue also called the Hubble Palette, and looks like this:






The second standard blend is HOO, or Hydrogen/Oxygen/Oxygen mapped to Red/Green/Blue, also called the "natural" palette as it weights hydrogen and oxygen more accurately to their respective colors, and looks like this:






A true "natural" color palette should also actually blend Ha into blue somewhat as well, and blend even less into green. This is because Hydrogen-alpha (Ha) is only one of many emission lines that hydrogen gas emits at when excited, and Hydrogen-beta (Hb) is another that emits very close to the OIII line. It tends to be fainter, so usually the blend is Red 100% Ha, Green 75% OIII, Blue 75% OIII + 25% Ha. The problem there is you have trouble getting proper star color (they all show up magenta), hence the reason for the more standard HOO blend, which produces better stars. 

As you might have noticed, I tend to spice things up a little bit with the "standard" blends.  Blending the two together to make a third blend was something I stumbled across mostly by accident, as I dragged the HOO blend over the SHO blend in PI, which renders the dragged window partially transparent. That gave me the idea for the third blend.


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## Don Haines (Sep 14, 2016)

jrista said:


> I haven't been posting my own images here much lately, as I have not had much clear sky this year. Not much at all. I've also moved on from the 5D III...but, I am still active. I have moved to a monochrome camera with LRGB and narrow band filters. I've had some clear nights finally, and managed to acquire some good data with the new camera. It's not a Canon, so I probably won't be sharing all my images from it here, but here is my latest:


Jon, I think that I can speak for everyone here..... Please post your non-Canon images with the explanations of how you did it. Technique and process are more important than which camera was used and you are both an inspiration and a mentor to the rest of us.


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## d (Sep 14, 2016)

Don Haines said:


> jrista said:
> 
> 
> > I haven't been posting my own images here much lately, as I have not had much clear sky this year. Not much at all. I've also moved on from the 5D III...but, I am still active. I have moved to a monochrome camera with LRGB and narrow band filters. I've had some clear nights finally, and managed to acquire some good data with the new camera. It's not a Canon, so I probably won't be sharing all my images from it here, but here is my latest:
> ...



+1

Yes please, indeed!


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## telemaq76 (Sep 14, 2016)

awesome, and sure keep posting ;D


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## weixing (Sep 14, 2016)

jrista said:


> I haven't been posting my own images here much lately, as I have not had much clear sky this year. Not much at all. I've also moved on from the 5D III...but, I am still active. I have moved to a monochrome camera with LRGB and narrow band filters. I've had some clear nights finally, and managed to acquire some good data with the new camera. It's not a Canon, so I probably won't be sharing all my images from it here, but here is my latest:
> 
> *Wizard Nebula*
> 
> ...


Hi,
Nice... 

My area had very serious light pollution, so didn't do any Astrophotography for a very long time. Recently, after reading a review of 7D2 for Astrophotography, I do a test shot using my Canon 7D2 and EF 100-400mm L II and the result looks promising. 

Since I already had a GOTO equatorial mount, might well start some shooting and see what can I get using my WO FLT-98 telescope (just brought a Field Flattener) and EF 100-400mm L II.

Have a nice day.


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## jrista (Sep 14, 2016)

Well thanks, guys.  I have more to share, I just gotta process it. 

Weixing...here is a little secret. If you live in a light polluted area, unless you are doing narrow band imaging, it doesn't matter what kind of camera you have. Noise is an interesting thing, in that the noise from all the various potential sources add together in quadrature. That means that if you have one noise term that is much higher than the others, then the others effectively do not matter.

Now, in the city...there is really only one noise term that matters most of the time: Light pollution! Sometimes, for certain cameras, dark current might still matter, and if it is an older camera like the 5D II, dark current might actually be worse than light pollution. (Imagine that!) However, with most modern cameras, dark current is low enough that it matters no more than read noise when imaging in a light polluted area.

Ntotal = SQRT(Sobject + Slightpollution + DC + Nread^2)

If you are at a dark site, where light pollution is very low, say 1e-/s, and object signal is 2e-/s then a 300 second exposure will give you:

Ntotal = SQRT(2e-/s*60s + 1e-/s*60s + 0.2e-/s*60s + 5e-^2) = 14.7e-

However if you are in the city, where light pollution could easily be 15e-/s or more:

Ntotal = SQRT(2e-/s*60s + 15e-/s*60s + 0.2e-/s*60s + 5e-^2) = 32.5e-

What happens if we reduce read noise?

Ntotal = SQRT(2e-/s*60s + 1e-/s*60s + 0.2e-/s*60s + 2e-^2) = 14e-
Ntotal = SQRT(2e-/s*60s + 15e-/s*60s + 0.2e-/s*60s + 5e-^2) = 32.2e-

Notice how dropping from 5e- to 2e- read noise didn't really help all that much in either case here. However it helped more at the dark site than in the city with light pollution. What happens if you reduce dark current (0.2e-/s is low, but it can get much, much lower...for example, the ASI1600 has only 0.006e-/s @ -20C):

Ntotal = SQRT(2e-/s*60s + 1e-/s*60s + 0.006e-/s*60s + 2e-^2) = 13.6e-
Ntotal = SQRT(2e-/s*60s + 15e-/s*60s + 0.006e-/s*60s + 5e-^2) = 32e-

Well, that helped reduce noise at the dark site...but it did not really help much in the city. What if we reduced both read noise and dark current to zero (impossible in reality, but it gives us an idea of what the ideal amount of noise would be):

Ntotal = SQRT(2e-/s*60s + 1e-/s*60s + 0.006e-/s*60s + 2e-^2) = 13.4e-
Ntotal = SQRT(2e-/s*60s + 15e-/s*60s + 0.006e-/s*60s + 5e-^2) = 31.94e-

The dark site example here is about as good as it can possibly get. Which means that even with 5e- and 0.2e-/s dark current initially, we were getting fairly close. However, in the city, the difference between having dark current and read noise, and not...is basically meaningless. 

Light pollution is the great normalizer. If you are in the city, technology doesn't matter. You can image with pretty much any camera, and get mostly the same results regardless of camera. A 7D II will perform much the same as a 6D, which will perform much the same as a D5300, etc.

The great enabler for city imagers...is narrow band filters used with a monochrome camera. With narrow band, you block out almost all LP...reducing it to a tenth of an electron per second or less. You can do in a couple of hours with a camera like the ASI1600 w/ 6nm or narrower Ha and OIII filters, what it could take you WEEKS to do with a DSLR in the city. 

So...if anyone is very interested in astrophotography, but is stuck in the city, remember two things:

A) It doesn't matter what camera you have...better cameras won't help. So, if you cannot get a mono camera and filters, then just use whatever you have. It will all be the same in the end.

B) If you can afford it, get a cooled monochrome camera and some narrow band filters! It will allow you to get really nice results in the city, and thanks to companies like ZWO, it doesn't have to be that expensive. I use the ZWO ASI1600MM-Cool myself. However ZWO has many other cooled mono cameras, some for only a few hundred bucks. Their electronic filter wheel is only two hundred bucks. And a hydrogen alpha filter will cost you a couple hundred bucks. You could get a fully functional monochrome imaging package for less than a grand...and you wouldn't have to struggle with LP any more.


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## scyrene (Sep 15, 2016)

jrista said:


> Well thanks, guys.  I have more to share, I just gotta process it.
> 
> Weixing...here is a little secret. If you live in a light polluted area, unless you are doing narrow band imaging, it doesn't matter what kind of camera you have. Noise is an interesting thing, in that the noise from all the various potential sources add together in quadrature. That means that if you have one noise term that is much higher than the others, then the others effectively do not matter.



I may be overreaching here, but can I play devil's advocate and say that light pollution is not noise? It's signal. Unwanted signal, but signal - a real, fairly constant element in the scene, not random, nor caused by the equipment. Is that fair?

Otherwise obviously I'm sure you're right. And it makes me feel better what you say. I've never been to a dark site, so my inferior equipment is okay (PS I am getting that astro cam you suggested, maybe next month; I need to work on my alignment and tracking first).


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## jrista (Sep 15, 2016)

scyrene said:


> jrista said:
> 
> 
> > Well thanks, guys.  I have more to share, I just gotta process it.
> ...



Any unwanted signal that is going to be removed from the image and also introduces noise, IS a noise. Here is a fuller formula:

SNR = S/N

Where S = signal, and N = noise.

SNR = (Sobject * Ccount)/SQRT(Ccount * (Sobject + Slightpollution + Sdarkcurrent + Nread^2))

Note the single term in the numerator: Sobject. That is the only signal we actually care about. That is the only signal we are going to keep. 

Note all the terms in the denominator: Sobject, Slightpollution, Sdarkcurrent, and Nread. Those are all *noise terms*. Why is Slightpollution only in the denominator, and not in the numerator? We could do that...however, that is not representative of what our image will look like once we OFFSET the light pollution. Why do we offset it? Because if we do not offset it, it increases the "signal shift" or "signal separation", which brightens the background. 

Consider this:






This is the Pleiades, two *single subs*, no processing. Imaged from my heavily light polluted red bortle zone back yard, as well as from my quite dark green bortle zone dark site. The increased "signal" from light pollution in these two unprocessed images is quite obvious in the left panel there. It should be noted...these two images have identical exposure. The object signal is almost the same in both, around 50-60e-. The light polluted image is much brighter purely because of the unwanted light pollution photons that were recorded. 

Now consider this:






This is the same two images (cropped to just the pleiades themselves). The only difference here, is I offset the light pollution. Notice how much noisier the left side panel, the image from my light polluted back yard, is compared to the dark site image? 

Light pollution alone is indeed a singal, and as a signal, it has SNR. It's own SNR is:

SNRlp = Slp/SQRT(Slp)

However, if we remove the signal part, we are just left with the noise:

Nlp = SQRT(Slp)

In the second set of images above, after offsetting the lp, we are left with all of that extra noise...and none of the extra signal.

So...light pollution IS a noise. You just have to understand the context within which it behaves only as a noise and not a signal.  

Oh, I would also offer that light pollution can be VERY INCONSISTENT within the frame. LP is the primary source of gradients in astro images. Gradients can wreak havoc on the underlying object signal, and make it very difficult to get an effective stretch, or for that matter, to effectively offset LP. If one corner of the image is say 2000 16-bit ADU darker than the other corner. When you go to offset the LP...you either end up with a very obvious gradient, from nearly black to a much brighter opposite corner or edge...and, worse, the gradient can be colored...maybe it's orangish-red, maybe it's a magenta-green gradient, maybe it's bluish (i.e. with the moon in the sky), etc.

LP is the insidious, mischievous bastard child of Loki of the astrophotography world. It injects itself into your data and wreaks havoc on everything, and can often make it impossible to pull out a usable signal unless you invest MASSIVE amounts of time into getting massive amounts of data to compound your signal so much that it finally overpowers all the LP gradients, excess noise and other issues. 

Another benefit of narrow band filters? They are nearly immune to LP in general, and are thus also nearly immune to gradients.  I don't even calibrate my NB data with flats...just a 25-dark master frame lately. The field structure is nearly perfectly flat when the data comes out of the camera, and PixInsight's DBE tool makes pretty short work of what minor gradients or vignetting may exist.


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## scyrene (Sep 15, 2016)

jrista said:


> scyrene said:
> 
> 
> > jrista said:
> ...



Hehe, you rewarded my cheekiness with a very full answer, that I did not deserve. Thanks 

Light pollution is a nightmare, and I agree, one of the worst aspects is how it varies across the sky (so any moderately wide shots or wider are very hard to correct for). Also in these parts, they've started replacing the narrowband sodium street lights with white LEDs :-\

Currently working on M31, which shows well here, despite LP. But it'll take a lot more clear weather to get anywhere near some of the shots on this thread... Still, it's good to have a challenge.

(PS I agree with narrowband filtering, it seems the way to go not having access to dark sites).


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## alexthegreek (Sep 16, 2016)

jrista said:


> alexthegreek said:
> 
> 
> > Here's my Andromeda galaxy done with my stock 500d (which is about to quit on me, sometimes it doesn't turn on and that will be the end of me) and an old Jupiter 21M 200mm I got for 50 euro.1 min at iso 800 f5.6 about 60 min integration time and about 40-50 (or so I think) darks.Im not sure about the number of darks because deep sky stacker does not seem to be loading the file lists I create with darkmaster correctly.1st group is empty(I've read that's normal), second is ok but the next group is missing a lot of darks!Any idea what's going on?
> ...



Thanks jrista!I use darkmaster because I have a darks library and so it combines the older darks with the darks I shoot on the same night.Plus it groups them based on temp


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## telemaq76 (Sep 19, 2016)

my last version of andromeda


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## d (Sep 19, 2016)

telemaq76 said:


> my last version of andromeda



Really nice, telemaq! May I ask how you imaged that one?

Cheers,
d.


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## meywd (Sep 19, 2016)

telemaq76 said:


> my last version of andromeda



beautiful, the colors are great, tbh photos of Andromeda are always a favorite to me, when I see it I feel like I will fall in the center of the galaxy, and it gives a 3D feel.


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## telemaq76 (Sep 20, 2016)

d said:


> telemaq76 said:
> 
> 
> > my last version of andromeda
> ...



thanks 
53x210 seconds with my canon 700d astrodon+cls filter
lens : canon 500f4 is 
mount : neq6pro
dark, flats offset
software : Iris then photoshop


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## jrista (Sep 21, 2016)

telemaq76 said:


> d said:
> 
> 
> > telemaq76 said:
> ...



Nice work, looks great! 

To be perfectly honest, looks really good considering you used a CLS filter. The CLS is a broadband nebular filter, and notches out the entire green/yellow part of the spectrum. I'm amazed you were able to get the core as nicely colored as you did with that filter in place.


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## jrista (Sep 22, 2016)

*Soul Nebula *

*2x1 Mosaic*

Integration: 2h37m30s / panel (5h15m total)
Camera: ASI1600MM-Cool
Filters: AstroDon 3nm Ha
Mount: Orion Atlas EQ-G (custom modded with belt drive)







A full-size crop:


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## alexthegreek (Sep 26, 2016)

I have a question for the more experienced in here.When I first started learning about astrophotography the first thing I learned was "You need darks,bias and flats to calibrate your lights" and I thought that was it.Then things like "You don't need bias frames as they are included in your darks" or "You MUST NOT use bias frames if you have dark frames" or "dont use anything as dark level is suppressed in sensor (which is true),read noise is already low (for some cameras anyway) and flats can be replaced with lens profiles (well if you are using a telescope that is not going to work).Now these people they all create amazing images and are involved in scientific projects or astrophotography software development so I trust they all know exactly what they are talking about, the problem is they dont agree with each other and that leads to confusion for a mere mortal that I am!So my question is what is your standard approach?Do you choose your method depending on your imaging conditions (for example temperature)?


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## jrista (Sep 26, 2016)

alexthegreek said:


> I have a question for the more experienced in here.When I first started learning about astrophotography the first thing I learned was "You need darks,bias and flats to calibrate your lights" and I thought that was it.Then things like "You don't need bias frames as they are included in your darks" or "You MUST NOT use bias frames if you have dark frames" or "dont use anything as dark level is suppressed in sensor (which is true),read noise is already low (for some cameras anyway) and flats can be replaced with lens profiles (well if you are using a telescope that is not going to work).Now these people they all create amazing images and are involved in scientific projects or astrophotography software development so I trust they all know exactly what they are talking about, the problem is they dont agree with each other and that leads to confusion for a mere mortal that I am!So my question is what is your standard approach?Do you choose your method depending on your imaging conditions (for example temperature)?



There is no single answer that works for every setup. I know Roger Clark frequently tells people they "don't need to use darks because the camera has on-sensor dark current suppression", for example. However, that is only true for much newer DSLRs, and in the cases where dark current is actually suppressed to a truly effective level that you can actually ignore dark current entirely is...well, basically ONE camera, and only in the winter months. However, that is usually not made very clear, and I know a lot of beginner astrophotographers who hear such advice, such as yourself, and end up confused and frustrated with their own astrophotography as a result.

There is a LOT of confusing rhetoric out there like that. The simple fact of the matter is, it really, really, really does depend on the camera you are using. However, here is one fundamental rule about darks that is true for pretty much every camera:



> A dark frame contains *more *than _just _the "dark current". Dark current is one of many aspects of the "dark signal" that every digital camera contains, and it is often the least important aspect. The more important aspects of "dark signal" include the fixed bias pattern (i.e. fixed banding), the fixed dark current pattern (i.e. hot and cold pixels), semi-random dark current pattern (i.e. signal interference from an external source, clock signal interference, etc.), and glows (i.e. amplifier glow). Subtraction of a dark, either a single dark frame or a properly constructed master dark frame, is about eliminating pattern noise, not about reducing the random dark current noise.



As a matter of fact, subtracting a frame of pure random noise from another frame of pure random noise actually results in MORE random noise...however, a small increase in random noise is usually VERY preferable to leaving the fixed pattern noises in place, as FPN is something our senses latch onto far more easily, as FPN is very unsightly and unnatural.

Dark current is technically a signal, that follows Poisson counting statustics, meaning that it effectively behaves the same as photons of light...it's noise is random. The random noise in dark current from most modern cameras is very low when the camera is operating at lower temperatures, low enough to not be of major concern. Additionally, if you stack many dark frames together, you average down the random noise, making it even less of a problem. Dark current grows consistently with time, and can introduce a growing offset in the total image signal as more dark current accumulates. Since dark current itself is Poisson, removing it is actually quite simple...you simply subtract the offset. That will remove the signal part, leaving behind only the extra dark current noise (which is usually very small). 

Bias is also a signal, however it is a fixed signal for the most part. It is the offset in each pixel that occurs due to the voltage applied to the pixels during readout. The purpose of bias is to ensure that there is enough of an offset from ZERO voltage to give room for noise to be noise, which can result in pixel values ending up smaller than they should be, as well as larger. This avoids clipping. The thing about bias is that every pixel and every row or column (usually column, due to how most sensor readout systems work) will have a different _*response *_to the applied voltage. This is where most vertical banding comes from...and this form of noise is a fixed pattern. The handy thing about true fixed pattern noise is it subtracts out easily. All you need is a clean master bias, or a clean master dark, and the bias pattern will be removed. 

A note about the sensor bias. EVERY frame created by the camera will always have the bias signal in it. Bias is an intrinsic trait of the sensor. A bias frame contains basically just the bias signal as well as read noise, and nothing else. A dark frame contains the bias signal, read noise, and the dark signal, which includes the dark current noise, any dark fixed pattern like hot and cold pixels or any fixed or semi-random banding in the dark, as well as any glows. A flat frame contains the bias signal, read noise, the dark signal, as well as the photoelectric flat signal. A light frame contains the bias signal, read noise, the dark signal, as well as the photoelectric image signal. The bias is in EVERY frame! Therefor, if you subtract only a master dark, you will be subtracting the dark signal as well as the bias, and all of the aggregate fixed pattern represented therein.

The only time when you need to use a discrete master bias is when you are using flat calibration without flat darks. There are several ways to calibrate...depends a lot on what you are doing. In my experience, narrow band imaging only needs a single master dark. There isn't enough light with narrow band imaging to really create huge problems with the *field*....so, you don't usually see vignetting, and if you are careful and keep things clean, you also usually won't have issues with dust motes. That means you can eliminate flat calibration in this case. 

Now, there are two other calibration options. In these two cases, flat calibration IS necessary. However, you can handle the flats in one of two ways. You can do a bias/dark/flat calibration, or you can do a light/dark and flat/flatDark calibration. The former can be used if you have minimal dark signal and/or are using very short exposures for your flats. You use a master bias to calibrate EVERYTHING...every dark frame, every flat frame, every light frame. You then further calibrate the lights by subtracting the calibrated master dark and dividing the calibrated master flat. This only works if you do not have any kind of glow...and glows, particularly amp glow, have become much more common these days (sadly...they used to be a thing of the past, however with all the video capabilities, it seems that amp glow has been reintroduced and seems to be a fairly endemic feature with video-capable cameras). If you have glows, then the other calibration path is usually better. Because the bias is included in every frame, you can create a master dark for your lights (and this master dark is usually reusable for two to six months as long as you can keep the temperatures well-matched), and you create another master dark for your flats. You then just calibrate with these two master darks, one for each type of frame, then further calibrate the lights by dividing out the master flat. You do not need a master bias in this situation.

In the end, calibration is about reducing the noise sources in each of your lights to just read noise and photon shot noise, as much as possible. You want to eliminate patterns, first and foremost...banding, hot/cold pixels, glows, any form of non-random, non-image structure, especially unnatural structures that the eye can latch onto. This is very important with stacking, as anything fixed in nature, vs. random, will actually be *reinforced *with stacking. If you do not eliminate fixed pattern noise, then you will hit a brick wall in regards to how many subs you can stack and still benefit from the noise reduction inherent in stacking (random noise is reduced as the SQRT(SubExposursStacked)). 

Fixed pattern noise will eventually show through the fainter background areas of an astrophoto extremely well, and it looks hideous. Calibrating with bias/dark/flat can increase random noise...however, if you use sufficient numbers of frames for each of your masters...such as 100 biases, 25-49 darks, and 36-49 flats, then you will average out the noise in those frames as well, so the increase in random noise in each calibrated light becomes quite small. If, for any reason, the contribution appears to large, you can always stack more frames into your masters...again, the random noise in the masters drops as the square root of the number of frames stacked.


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## alexthegreek (Sep 27, 2016)

Jrista it's a pleasure to have you here!


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## Don Haines (Sep 27, 2016)

alexthegreek said:


> Jrista it's a pleasure to have you here!


+70!


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## Click (Sep 27, 2016)

alexthegreek said:


> Jrista it's a pleasure to have you here!



I totally agree with you


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## rpt (Sep 29, 2016)

Don Haines said:


> alexthegreek said:
> 
> 
> > Jrista it's a pleasure to have you here!
> ...


+70 from me too. Always a pleasure to have Jrista explain stuff.


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## jrista (Oct 10, 2016)

Thanks, guys.


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## telemaq76 (Oct 20, 2016)

ngc 7635 i took 64*3 min with h-alpha
i added it to a color version i took few monthes ago
i "faked" the colors for the bubble, just a try


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## lion rock (Oct 21, 2016)

I totally agree that jrista is a tremendously invaluable person here on CR. A great wealth of deep sky photography knowledge.
May I ask if you would kindly show your setup to shoot these fascinating photos? I want to at least learn of the equipment and how to set them up to shoot some for myself, if the I can afford the equipment.
Much thanks.
-r


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## Click (Oct 21, 2016)

telemaq76 said:


> ngc 7635 i took 64*3 min with h-alpha
> i added it to a color version i took few monthes ago
> i "faked" the colors for the bubble, just a try



Awesome. Well done, telemaq76. 8)


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## jrista (Oct 26, 2016)

lion rock said:


> I totally agree that jrista is a tremendously invaluable person here on CR. A great wealth of deep sky photography knowledge.
> May I ask if you would kindly show your setup to shoot these fascinating photos? I want to at least learn of the equipment and how to set them up to shoot some for myself, if the I can afford the equipment.
> Much thanks.
> -r



My personal setup looks like this:


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## alexthegreek (Oct 26, 2016)

Well that looks terrific!!Howcome you're not using a refractor telescope instead of a photographic lens?It doesn't look that your budget is very limited as that lens probably costs a lot more than most refractors.And another thing I was wondering...has anyone in here had any experience with a sony sensor dslr?We know at 400 iso and below it is better than the canons but at 800 or 1600?Is there something to be gained by using one?


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## LordofTackle (Oct 26, 2016)

jrista said:


> lion rock said:
> 
> 
> > I totally agree that jrista is a tremendously invaluable person here on CR. A great wealth of deep sky photography knowledge.
> ...



Didn't you move to a dedicated astro-cam recently?? Or did I get that wrong? 

Anyway, as usual your post are really really helpful, greatly appreciated. 

Sebastian


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## lion rock (Oct 26, 2016)

Thanks, jrista!
I think I still have half a chance to shooting the sky with my 70-200. I think I have to seriously prepare myself this winter when the sky is clear.
As alexthegreek expressed surprise that you don't use a refractor telescope, I am curious why you don't use a reflector scope. Could you elaborate your reasons and insight to these selections?
Thanks
-r


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## East Wind Photography (Oct 27, 2016)

jrista said:


> lion rock said:
> 
> 
> > I totally agree that jrista is a tremendously invaluable person here on CR. A great wealth of deep sky photography knowledge.
> ...



Look at that stack of washers! . Do you really use the 600 with the 2x teleconverter?


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## jrista (Oct 30, 2016)

alexthegreek said:


> Well that looks terrific!!Howcome you're not using a refractor telescope instead of a photographic lens?It doesn't look that your budget is very limited as that lens probably costs a lot more than most refractors.And another thing I was wondering...has anyone in here had any experience with a sony sensor dslr?We know at 400 iso and below it is better than the canons but at 800 or 1600?Is there something to be gained by using one?



My lens is actually better than many refractors. It also has a significantly larger aperture than most refractors, and aperture is critical in AP. Bigger photon bucket.  To get a comparable refractor, I'd need to spend about $7k or so anyway, and the aperture would actually be smaller. To get a refractor with a similar aperture, I'd need to spend about $11k (there are not many 150mm aperture refractors out there...the TEC140 has a 140mm aperture and is about $6000 (and with necessary accessories, a bit more), and there is the Officina Stellare HiperAPO 150mm, which is almost $11k). So I wouldn't have saved much with a "real" refractor. 

There are other benefits with the Canon lens. The Fluorite elements. The nanocoatings (no current refractor uses nanocoatings yet, but it's actually a big deal for transmission) on the internal elements. The corner-to-corner field and color correction. There are a lot of things about the Canon superteles that actually blow many telescopes out of the water. Hence the reason I use it as my telescope.  

Regarding Sony cameras. Sony's sensors are fantastic, and actually the companies ZWO and QHY are working on putting the Sony 36.7mp full frame sensor into dedicated, cooled and regulated astro camera bodies. So soon here, we will have the ability to run the same sensor as the D810 in a camera body that can cool the sensor 45 degrees C below ambient. That will make for one hell of an astrocamera. DSLRs won't be able to touch it. 

Sony CAMERAS, on the other hand, are not actually that good for astro. It isn't because of the sensor, it's because of the hard-coded processing that the BIONZ X chips do. They force spatial filtering on all exposures longer than 30 seconds, and since most astro exposures are several minutes at least, that causes problems. For astro, you want the purest data you can get, that has been screwed with the least, for maximum linearity and detail. Sony has been slowly improving things, but until they disable the forced spatial filtering for exposures longer than 30 seconds, i don't recommend them for astro. 

For astro with a DSLR in general, I recommend ISO 1600. That gives you a good balance of low read noise (on cameras that use Sony sensors, often as little as 2e- or less!) and decent dynamic range. You can use shorter exposures as well, which can allow you to maximize resolution and avoids problems with poor tracking that most low end German Equatorial mounts have. It's best for beginners, but even advanced imagers will usually use shorter exposures these days.


----------



## jrista (Oct 30, 2016)

LordofTackle said:


> Didn't you move to a dedicated astro-cam recently?? Or did I get that wrong?
> 
> Anyway, as usual your post are really really helpful, greatly appreciated.
> 
> Sebastian



I did. This is an old photo from a couple years ago. I am currently using this camera, the ASI1600, and filter wheel, the Atik EFW2:



























Inside the filter wheel are AstroDon LRGB E-series Gen2 filters, and AstroDon Ha, SII and OIII 3nm narrow band filters.


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## jrista (Oct 30, 2016)

lion rock said:


> Thanks, jrista!
> I think I still have half a chance to shooting the sky with my 70-200. I think I have to seriously prepare myself this winter when the sky is clear.
> As alexthegreek expressed surprise that you don't use a refractor telescope, I am curious why you don't use a reflector scope. Could you elaborate your reasons and insight to these selections?
> Thanks
> -r



I did use a reflector for a while. I still have the AstroTech 8" Ritchey-Cretien (AT8RC), however I need to sell it. I am not sure if it is just that the scope is too large for my mount, or what, but I have not had much luck using that scope so far. RCs (Ritchey-Cretien Scopes) use two hyperbolic mirrors. As such, they must be PERFECTLY aligned in order to get good results, however collimating an RC is a royal pain in the butt. Additionally, this is one of the "consumer grade" RCs...so they are not built to high tolerance and their collimation does not seem to hold well. So even when I would get it properly collimated, within a couple of days it would slip back out of collimation.

Once I sell it, I am planning on getting a Celestron EdgeHD SCT scope. These are also mirror scopes, although not pure mirrors like an RC (they have an optical corrector plate in the front of the scope). SCTs use spherical mirrors, though, so collimating is extremely easy. The primary mirror in an SCT, unlike an RC, is used to flocus, so it can "float" a little free, resulting in something called mirror flop (the mirror can shift a little during tracking). Thing is, I would MUCH rather deal with mirror flop (and, according to Celestron, if you handle focusing properly, there is no mirror flop with their EdgeHD scopes) than deal with the difficulty in collimating two hyperbolic mirrors.  

I am not sure I'll get the SCT, though. One thing that is a problem inherent to all mirror scopes is cooldown. The primary mirror and the entire OTA has to cool. That results in focus shift. The bigger the scope, the more significant the heat mass that has to cool. If I lived in an area of more stable temperatures, I'd probably already have a Celestron EdgeHD...however here in Colorado, we have such huge temperature swings (lately, 82F during the day, 40F at night!!) that trying to cool a large mirror scope is extremely difficult. I think that may the other part of my problem with the RC...it cools throughout the entire night, and cools so much and the focus shifts so much that I can't keep up with it. Not when using 10, 20, 30 minute exposures. The focus will shift so much DURING the exposure that the exposures are just bad, the stars are very bloated and everything, very little detail (sometimes WORSE detail than my shorter 600mm lens!)

So, I may just be sticking with refractors. I can pick up a longer refractor for higher resolution work, but refractors in general (like my 600mm lens, which IS basically a large refracting telescope) are just easier to deal with. They do have a heat mass and do cool, but I find that my 600mm lens settles within 3 hours, and it's rate of cooling is slow enough that I can get longer exposures without too much problem.


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## jrista (Oct 30, 2016)

East Wind Photography said:


> Look at that stack of washers! . Do you really use the 600 with the 2x teleconverter?



Yeah, the washers were meant to be temporary, however over the long term, they have actually performed perfectly, so I never replaced them with a solid block of metal like I had intended to. 

As for the 2x TC. I have, in the past. Even with the 600mm lens and the 2x TC III...the loss in IQ is a bit too much for me, so I don't use it. I actually haven't used my 2x TC III at all for over a year...so I should really sell the darn thing.


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## lion rock (Oct 30, 2016)

jrista,
Thanks for the detailed reply.
I can understand the expansion/contraction due to ambient thermal changes.
I'm interested in looking at the night sky and stars for a long time (since the Star Trek days), but have not really delve into it. I have a neighbour, he was my brother's grad school advisor in California, and he showed me his 8 inch reflector which triggered my interest again. I may, so many wants and so limited resources and time, get a minimal cost 8 inch reflector with a single parabolic mirror. My needs are totally "pro-amateur", so an inexpensive unit would be fine. Hopefully, I don't have to worry about temperature change too much.
Thank you for the insight. You shoot pure fantastic deep sky photos!
-r


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## jrista (Oct 31, 2016)

lion rock said:


> jrista,
> Thanks for the detailed reply.
> I can understand the expansion/contraction due to ambient thermal changes.
> I'm interested in looking at the night sky and stars for a long time (since the Star Trek days), but have not really delve into it. I have a neighbour, he was my brother's grad school advisor in California, and he showed me his 8 inch reflector which triggered my interest again. I may, so many wants and so limited resources and time, get a minimal cost 8 inch reflector with a single parabolic mirror. My needs are totally "pro-amateur", so an inexpensive unit would be fine. Hopefully, I don't have to worry about temperature change too much.
> ...



If you are just starting AP, then the easiest way to start is to get a small refractor. Something like the William Optics Star71, or if you are willing to spend a bit more money for quality, a StellarVue SV80ST. Refractors are small, light weight, and easy. Reflectors are larger, heavier, both of which affect tracking, require collimation, and in the case of newtonians, have much larger moment arms which affects tracking. Trying to learn AP on a larger scope is very difficult. Some people manage it, but I just want you to be aware of what you are stepping into if you pick up an 8" Newt. It won't be easy. 

Also remember, you must have a tracking mount if you are going to be imaging at anything much longer than about 50mm. If you are imaging longer than 200mm, a decent german equatorial will be necessary. The lowest end I like to recommend is the Orion Sirius, which is about a grand, and can handle at most a 30lb load. For imaging, you don't really want to load a mount with more than about 50% of that maximum, so 15, maybe 18 pounds. An 8" Newt would require a more sturdy mount, probably something in the $2k range (say the Orion Atlas Pro). A small refractor, however, would be perfect on the Orion Sirius.


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## lion rock (Oct 31, 2016)

jrista,
Thank you again for the pointers. Really appreciate the advice.
This is what I'm lusting after, Meade R8 LX70 8" Reflector on LX70 Equatorial Mount, at a reasonable amateurish cost. It has a low cost drive option, so I think it is adequate for me presently. (Sorry, my GAS fund is for a long white!)
If you think that this model is really below par, I'll look into the ones you suggest.
I thank you for taking time to give me your wisdom.
-r



jrista said:


> If you are just starting AP, then the easiest way to start is to get a small refractor. Something like the William Optics Star71, or if you are willing to spend a bit more money for quality, a StellarVue SV80ST. Refractors are small, light weight, and easy. Reflectors are larger, heavier, both of which affect tracking, require collimation, and in the case of newtonians, have much larger moment arms which affects tracking. Trying to learn AP on a larger scope is very difficult. Some people manage it, but I just want you to be aware of what you are stepping into if you pick up an 8" Newt. It won't be easy.
> 
> Also remember, you must have a tracking mount if you are going to be imaging at anything much longer than about 50mm. If you are imaging longer than 200mm, a decent german equatorial will be necessary. The lowest end I like to recommend is the Orion Sirius, which is about a grand, and can handle at most a 30lb load. For imaging, you don't really want to load a mount with more than about 50% of that maximum, so 15, maybe 18 pounds. An 8" Newt would require a more sturdy mount, probably something in the $2k range (say the Orion Atlas Pro). A small refractor, however, would be perfect on the Orion Sirius.


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## telemaq76 (Nov 1, 2016)

the seven sisters
42x4 min + darks, flats, offsets


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## Click (Nov 1, 2016)

Beautiful picture, telemaq76.


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## rpt (Nov 2, 2016)

telemaq76 said:


> the seven sisters
> 42x4 min + darks, flats, offsets


Lovely picture. 

What did you shoot it with? What was the focal distance of the lens?


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## Mr Bean (Nov 2, 2016)

jrista said:


> I did use a reflector for a while. I still have the AstroTech 8" Ritchey-Cretien (AT8RC), however I need to sell it. I am not sure if it is just that the scope is too large for my mount, or what, but I have not had much luck using that scope so far. RCs (Ritchey-Cretien Scopes) use two hyperbolic mirrors. As such, they must be PERFECTLY aligned in order to get good results, however collimating an RC is a royal pain in the butt. Additionally, this is one of the "consumer grade" RCs...so they are not built to high tolerance and their collimation does not seem to hold well. So even when I would get it properly collimated, within a couple of days it would slip back out of collimation.



Ah, that bought back memories. 30 years ago, as a hobby, I used to make telescopes (reflectors). I started to make a Ritchey-Cretien but never finished it. I still have the primary (with hole cut) and roughly ground to the shape I needed (done with a diamond edged lens cutting wheel - used on a machine called a "generator"). The good 'ol days 

And thanks for the detailed info you provide in your posts jrista.


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## Mr Bean (Nov 2, 2016)

telemaq76 said:


> the seven sisters
> 42x4 min + darks, flats, offsets


Love the image


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## telemaq76 (Nov 2, 2016)

rpt said:


> telemaq76 said:
> 
> 
> > the seven sisters
> ...



i used my canon 700da+500mm f4
22x4 minutes + dark, flat offset
new picture of california nebula


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## Click (Nov 2, 2016)

This is a beautiful picture. Well done, telemaq76.


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## rpt (Nov 3, 2016)

telemaq76 said:


> i used my canon 700da+500mm f4
> 22x4 minutes + dark, flat offset
> new picture of california nebula


Cool! Thanks. And a lovely picture.


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## jrista (Nov 3, 2016)

lion rock said:


> jrista,
> Thank you again for the pointers. Really appreciate the advice.
> This is what I'm lusting after, Meade R8 LX70 8" Reflector on LX70 Equatorial Mount, at a reasonable amateurish cost. It has a low cost drive option, so I think it is adequate for me presently. (Sorry, my GAS fund is for a long white!)
> If you think that this model is really below par, I'll look into the ones you suggest.
> ...



The LX70 by default is not a powered mount. There is a drive addon, but it is completely, totally worthless for imaging. Additionally, a scope that large and heavy on a mount that tiny is WAY overloaded. There is not a chance you would be able to use the $700 mount+scope kit to do any imaging.

The bare-bones minimum mount I recommend for use for astrophotography is the Orion Sirius EQ-G. That mount alone is $1100 I think. A decent refracting telescope for imaging purposes comes in around a grand, however the one I like to recommend most often, the SV80ST, is about two grand. So the bare bones imaging kit with a refracting telescope is $3000. IF you want to get into DSO imaging and do it right, and reliably. 

You can start more cheaply than that, for sure. Don't even bother with the low end visual kits, like the Mead LX70 ones. I've used similar kits, tried them back in 2013 when I was first getting interested. Totally not worth the hassle. They are visual only. You can pick up a Polari, SkyTracker, or Star Adventurer tracker for about $400-500. Those are very basic trackers, once polar aligned, they can track a DSLR with a lens across the sky, for wide field imaging. You could put up to maybe a 200mm lens on a DSLR on one of those things, and get about 2 hours of good tracking. You can use the camera and lenses you have, for the most part, as well. So they are about the cheapest way to get into astrophotography.

It's not really cheaper than that, though. If you picked up a used Orion Sirius mount, you might spend about $700 or so. If you picked up a used SV80ST, you might spend $900 to $1200. Going used, that is probably the cheapest you can get a decent mount and scope for. You might be able to pick up an AstroTech refractor for cheaper...but they are pretty small, 65mm apertures, fairly slow. I don't like to recommend anything smaller than an 80mm aperture when it's a refractor. I wouldn't think about reflectors yet. They are much larger, heavier, usually longer, and the higher magnification requires things like guiding and more skill with AP to get usable data out of them. 

Start out right...with a proper mount, a small 80mm refractor, and adapt your DSLR, and learn the ropes first.


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## lion rock (Nov 3, 2016)

jrista,
Thank you for the advice.
I really have to purpose my funds wisely, and if you think my selection is too simplistic, I'll just shelf it and put my funds into a longer prime as I really AM lusting after. I did hesitate to get the Meade, deep in my heart, I know the product won't be superior with that cost, thus I never made the move. Thanks for setting me straight. I now have to play with my neighbours scope.

I do have the SkyTracker and it ought to pair well with my 70-200 with my 5D3 or 7D2 to give a better "focal length." I'll try my setup when the night sky becomes clearer in the winter months.

In the meantime, I'll have to admire your shots. Hope you'll keep posting them.
Thank you much again for the advice.
-r


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## jrista (Nov 3, 2016)

lion rock said:


> jrista,
> Thank you for the advice.
> I really have to purpose my funds wisely, and if you think my selection is too simplistic, I'll just shelf it and put my funds into a longer prime as I really AM lusting after. I did hesitate to get the Meade, deep in my heart, I know the product won't be superior with that cost, thus I never made the move. Thanks for setting me straight. I now have to play with my neighbours scope.
> 
> ...



If you have the SkyTracker, then you can actually do a lot with that. At 200mm, you can get some pretty amazing large field nebula shots. Such as framing both Heart and Soul nebulas in a single image. I would definitely give it a try! There are tons of regions in the sky packed with hydrogen gas that will fill a 200mm field quite nicely.


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## lion rock (Nov 3, 2016)

jrista,
Thanks, that gives me a lot of confidence to go with my current lens. I'll shoot some with what I have now.
I'll also try with both my FF and cropped frame and my 1.4X and 2X multiplier. I'm excited.
-r




jrista said:


> If you have the SkyTracker, then you can actually do a lot with that. At 200mm, you can get some pretty amazing large field nebula shots. Such as framing both Heart and Soul nebulas in a single image. I would definitely give it a try! There are tons of regions in the sky packed with hydrogen gas that will fill a 200mm field quite nicely.


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## jrista (Nov 5, 2016)

*Taurid Meteor through the heart of Pleiades*

This new ASI1600 is an incredibly sensitive camera, so it's forced me to use shorter exposures. I was acquiring short 10 second L filter subs two nights ago, and while blinking through them with PixInsight to find and discard bad subs, I noticed something bright flash through one of the frames. When I investigated more closely, I found this amazing sequence:






Meteorite, I believe a Taurid, a minor meteor shower which peaked tonight, zipped through my frames leaving a smoking plasma trail behind, corkscrewing off the right side of the field.


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## rpt (Nov 5, 2016)

Wow! Congratulations! That was something!


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## Valvebounce (Nov 5, 2016)

Hi Jon. 
That is really cool, loving the smoking trail, and the fact that you took the effort to share it with us, thank you. 

Cheers, Graham. 



jrista said:


> *Taurid Meteor through the heart of Pleiades*
> 
> This new ASI1600 is an incredibly sensitive camera, so it's forced me to use shorter exposures. I was acquiring short 10 second L filter subs two nights ago, and while blinking through them with PixInsight to find and discard bad subs, I noticed something bright flash through one of the frames. When I investigated more closely, I found this amazing sequence:
> 
> ...


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## lion rock (Nov 5, 2016)

jrista,
What a catch!
Hope its not a once in a life time shot.
Well done, not that you plan for, but nature often gives us a surprise.
-r


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## Click (Nov 5, 2016)

Cool capture.  Well done, Jon.


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## rrcphoto (Nov 5, 2016)

jrista said:


> *Taurid Meteor through the heart of Pleiades*
> 
> This new ASI1600 is an incredibly sensitive camera, so it's forced me to use shorter exposures. I was acquiring short 10 second L filter subs two nights ago, and while blinking through them with PixInsight to find and discard bad subs, I noticed something bright flash through one of the frames.



I was checking out that camera. there were some reports that it has an IR filter stack attached - was that the case with yours? there was confusion over whether or not that the was the color versus monochrome imager though.

I was thinking of getting the color - simply because of hyperstar compability.


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## jrista (Nov 5, 2016)

rrcphoto said:


> jrista said:
> 
> 
> > *Taurid Meteor through the heart of Pleiades*
> ...



Hyperstar III has the filter drawer system. The mono is vastly more efficient than the color, and with the filter drawer, you could do narrow band f/2 imaging. I know a couple people have done that so far.

As for IR filtering, no, not on this camera. There is an AR (anti-reflective) window built into the body, and there is just plain glass covering the sensor for protective purposes. But the sensitivity range of the sensor is full, reaching deep into the NIR range. I think that the original camera design included an IR cutoff window instead of just an AR window, but that was changed for the final design, IIRC from early discussion I had with Sam Wen of ZWO. 

ZWO offers their own set of ASI1600-optimized LRGB filters. The RGB filters of course cut off outside of the color channel bandwidth. The L filter cuts off hard at the UV and IR ranges. Same goes for most LRGB filter sets from Baader, Astronomik, AstroDon, etc.


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## East Wind Photography (Nov 12, 2016)

Jon that is a once in a million sequence you got. Really proves that ionized trails are real and visible and not some kind of eye trickery.

That might even be worth publishing as individual sequences.


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## StudentOfLight (Nov 14, 2016)

Experimenting with the 80D and the 135mm f/2. This is a interesting combo as it puts more pixels on target than my Tamron 70-200m with the 6D. The 80D also has a new low read-noise sensor which I thought could be good for deep sky. To compensate for the lower full-well capacity of the smaller pixels I used ISO 800 instead of my typical ISO 3200 or ISO 6400. Not happy with the amount of highlight detail. Maybe the lens is just not sharp enough for 3x Drizzle??? Hopefully my local currency will improve a bit more then I can get a tracking mount.

The most notable feature in the LMC is the Tarantula Nebula https://en.wikipedia.org/wiki/Tarantula_Nebula, which is the most active star-forming region in our local group of galaxies. The 200 parsec size of this extra-galactic object is hard to fathom. To put it in context, if it were as close as the Orion nebula then it would appear 40 times larger than the full moon in the night sky.




2016-11-09 - Large Magellanic Cloud by Omesh Singh, on Flickr


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## jrista (Nov 15, 2016)

StudentOfLight said:


> Experimenting with the 80D and the 135mm f/2. This is a interesting combo as it puts more pixels on target than my Tamron 70-200m with the 6D. The 80D also has a new low read-noise sensor which I thought could be good for deep sky. To compensate for the lower full-well capacity of the smaller pixels I used ISO 800 instead of my typical ISO 3200 or ISO 6400. Not happy with the amount of highlight detail. Maybe the lens is just not sharp enough for 3x Drizzle??? Hopefully my local currency will improve a bit more then I can get a tracking mount.
> 
> The most notable feature in the LMC is the Tarantula Nebula https://en.wikipedia.org/wiki/Tarantula_Nebula, which is the most active star-forming region in our local group of galaxies. The 200 parsec size of this extra-galactic object is hard to fathom. To put it in context, if it were as close as the Orion nebula then it would appear 40 times larger than the full moon in the night sky.



This is a great start, Student! Deep sky astrophotography is quite challenging. Especially if you are imaging with any kind of light pollution (city light, bright moon, even bright flares from oil & gas drilling.) The Magellanic Clouds are actually relatively faint overall, with a few bright spots like Tarantula.

My recommendation is NOT to bother with drizzling. Drizzling requires a lot of data to really be done effectively. If your sub count is too sparse, drizzling will actually increase noise, and it could introduce artifacts. This is particularly true with 3x drizzling. On top of that, you are needlessly expanding memory and storage usage by expanding resolution like that...and I can tell you you don't need it. It is best to use your full frame, along with effective calibration (particularly dark calibration, as DSLRs, even modern ones, have higher dark current as they are not cooled to sub-zero temperatures). You can calibrate a number of ways...however one of the simplest is to use the in camera LENR (Long Exposure Noise Reduction). This will double the length of each sub, however it is the best way to get well-matched dark calibration. There will be a slight increase in random noise, however that is usually preferable to keeping all the nasty pattern noise around, which tends to be particularly egregious in Canon DSLRs (the 7D II seems to be the lone exception so far.) 

I would also recommend you go back to the higher ISO. I would actually recommend ISO 1600, as that seems to be the sweet spot for most Canon DSLRs (although to be honest, I don't know the noise profile of the 80D off the top of my head.) Anyway, with ISO 1600, you can use shorter subs, which will kind of balance out the waiting game if you opt to use LENR. Depending on where you are, you may only be using 30-60 second subs. With LENR, they would be 60-120 seconds. Then it is just a matter of getting as many of them as you possibly can. You want LOTS of them. I like to go in lock-step with noise reduction factors, which is the square root of the subs stacked. I would say get no less than 36 subs (reduces noise by a factor of 6), but you could go for 49 (7x reduction), 64 (8x reduction), 81 (9x reduction) or 100 (10x reduction). Reducing noise through stacking is key to getting good astrophotography results. With shorter subs, say 30 seconds, plus LENR so 60 seconds, you could get 100 subs in 1h40m.

That is a decent start...however if you are imaging from or near a city, less than two hours is usually not enough to really go deep on a faintish object like the Magellanic Clouds. Generally speaking, I encourage beginners in or near the city to aim for four hours at a minimum. The deeper into the city you are, the more data you will really need to get decent results. I acquired 10, 14, in a couple cases 18 hours of data with my 5D III when I was still imaging in the city!

If you are using a DSLR for imaging, the BEST solution is to just get the heck out of the city. City light pollution is the bane of astrophotographers. There is really only one solution to it: More and more and more and ever more exposure time. You can sometimes use a larger lens with a larger physical aperture, however that usually comes with a change in FoV as well, which can require mosaicing if you really want a big wide field, and that increases the time to produce a final image as well. The solution is to just get rid of the LP, which means getting away from it. Driving 30-40 minutes out from the edge of town is usually sufficient to get you to nice, dark rural skies. From there, you will usually only need about two hours of data, and you'll be golden!


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## StudentOfLight (Nov 15, 2016)

I generally do not have sufficient focal length for deep sky objects so I usually end up drizzling the interesting portion of frame. I previously shot the LMC under similar LP conditions with my 6D and Tamron 70-200 at 70mm (102x6s).



LMC (102x 6s) by Omesh Singh, on Flickr 

The most notable difference is that the stars were not round with the 6D+Tamron image. I suspect it is due to some residual tilt in the IS mechanism as I always get stretching in my images from top left to bottom right.

Regarding ideal settings for the 80D, I read this on DPReview:
https://www.dpreview.com/forums/post/57481095 
I'm interested to see how it does at ISO100-200 with long exposure tracked images. 

Wouldn't you get the best results on an 80D with an ETTR approach at a lower ISO setting?


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## jrista (Nov 16, 2016)

StudentOfLight said:


> I generally do not have sufficient focal length for deep sky objects so I usually end up drizzling the interesting portion of frame. I previously shot the LMC under similar LP conditions with my 6D and Tamron 70-200 at 70mm (102x6s).
> 
> 
> 
> ...



Hmm. I am not sure that Jerry nor Roger are correct in that post. Canon has always, to my knowledge, used a 512 ADU 14-bit offset. I've been measuring DSLR data for years now, and I always make sure to measure in the proper bit depth, and across countless Canon DSLRs, I've measured a bias offset of 512 ADU (14-bit). 

I think people make the common mistake of converting the original RAW DSLR data into 16-bit, or the mistake of processing it in 16-bit space. Interestingly, the conversion factor between 14-bit and 16-bit is 4 (2^2), and 512*4 = 2048. I do not believe, at least not with any cameras since the 5D II or around there, that Canon has used a 2048 ADU offset.

If Roger is correct that Canon is using a lower offset at ISO 100 and 200, my guess is it would be a 128 ADU 14-bit offset. With lower read noise, that would certainly be possible. It also seems logical to keep a larger offset at higher ISO settings, which amplify noise more, and need more "buffer" room to avoid clipping the signal anyway. I haven't read anything specific to that effect myself, so I honestly cannot say what Canon may have really done with the 80D.

My opinion on which ISO is best is this, and actually in line with Roger's opinions most of the time:

It is better to "oversample" each electron of true signal, than to "undersample" them. By that I mean, you want your gain to be high enough that you are amplifying each electron by a factor of two, if not more. At low ISO, you are, for lack of a better term, "attenuating" the signal, since in most cases you must convert many electrons into each output ADU (analog to digital unit). This is low gain, high quantization. You are quantizing, or grouping together and effectively "squashing", many electrons together and losing a certain amount of information they held when they were separate and distinct.

This is not ideal for astrophotography, since we are chasing extremely faint details, and every single electron matters. It is entirely possible that at a low ISO, say ISO 100, you are converting 2, 3, 5, maybe even more electrons (depends on the pixel size and architecture) into one ADU. Technically speaking, it is possible to recover precision by stacking lots and lots of subs. However that is at odds with using a lower ISO, which requires longer exposures, which means you tend to get fewer of them. 

While from a read noise standpoint alone, you may have low read noise at low ISO with a supposedly "isoless" camera, from an actual functional standpoint, ISO 100 is absolutely NOT the same as ISO 800, or 1600, etc. ISO 100 is going to have poor representation of fine, faint details. ISO 1600 is going to have good representation of fine details. Quantization error is also usually going to be lower at higher gain. 

To preserve the full fidelity of the signal, and not lose any of the fineness of detail that each and every individual electron holds, you want to use a higher ISO. You generally want to "sample" each electron by a factor of 2-3x, meaning for each electron "input" into the ADC unit, you want to get 2-3 ADU out. There is always going to be some amount of quantization error (not even unity gain is free of quantization error, and it usually isn't selectable anyway), however relative to the scale of each electron at a higher gain, quantization error tends to be much smaller than at lower gain. So there are benefits all around when using higher gain, and all of them are more conducive to acquiring the best data for the kind of ultra faint signals you get with astrophotography. 

I don't ever recommend using low ISO for AP anymore. I also don't generally recommend using extremely high ISO settings, as you not only lose dynamic range, but FPN has a gain component and it can get much worse at higher ISO settings. This is particularly true of any secondary amplifiers are used in downstream electronics, which will amplify any signal and noise coming out of the pixels (and Canon definitely uses a secondary amp at high ISO settings). The sweet spot is usually ISO 800, 1600, maybe 3200 on some select few cameras with low FPN.


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## StudentOfLight (Nov 16, 2016)

jrista said:


> StudentOfLight said:
> 
> 
> > I generally do not have sufficient focal length for deep sky objects so I usually end up drizzling the interesting portion of frame. I previously shot the LMC under similar LP conditions with my 6D and Tamron 70-200 at 70mm (102x6s).
> ...


Could I share a couple of RAW files with you to help determine the best ISO to use with the 80D? There is so little info out on this camera. Just tell me what you need.


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## jrista (Nov 17, 2016)

I can actually do a full evaluation if you want. It is actually pretty easy. I can evaluate for several different ISOs if you wish.

What I would need for each ISO setting:

2 flats
2 biases (dark frame, shortest exposure possible)
2 darks (dark frame, one at say 30 seconds, one at say 300 seconds, so I can measure dark current rate)

If you get me several sets of such files, one set at least for each ISO, I can get you info about the true gain (e-/ADU), true read noise, actual dark current rate, etc. I can also get FWC, which will allow me to determine dynamic range. 

For most accurate results, three distinct sets of data for each ISO would allow me to give you an average of the three sets, which would give you more realistic expectations.


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## ISO64 (Nov 17, 2016)

Jon,

That smokin' trail is really the first dynamic astronomy photo that I've seen!!! As they say, happy go lucky!
Thanks for sharing.


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## jrista (Nov 17, 2016)

ISO64 said:


> Jon,
> 
> That smokin' trail is really the first dynamic astronomy photo that I've seen!!! As they say, happy go lucky!
> Thanks for sharing.



Thanks!  I am definitely not the first to create an animated astro photo. There are actually guys who "hunt the smoke" I guess you could say, who have a number of little GIF videos of ultra wide field milky way images with smoking meteors in them.

I think I may be the first to actually capture a sequence in a narrow field DSO image, though. New technology is a wonderful thing!


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## jrista (Nov 17, 2016)

*Andromeda Galaxy*

One of my latest images. This is a classic object, but one of the first LRGB images I've made with my new mono camera. Full fill factor for both the luminance (L) channel, which is where most of the integration time goes and where you optimize SNR, detail, etc. And full fill factor (means 100% of the pixels are used) for all three color channels. This is in contrast to a normal DSLR, which has a 50% green and 25% red/blue fill factor, which greatly reduces the sensitivity in those channels.

The data is still light polluted, however I was a bit surprised at how nice it turned out despite that fact:


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## Ryananthony (Nov 17, 2016)

Jrista, words can not describe how blown away I am by that image.


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## lion rock (Nov 17, 2016)

jrista,
Gorgeous! Gorgeous! Gorgeous! Gorgeous! Gorgeous! and so on ...
-r


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## Don Haines (Nov 17, 2016)

jrista said:


> *Andromeda Galaxy*
> 
> One of my latest images. This is a classic object, but one of the first LRGB images I've made with my new mono camera. Full fill factor for both the luminance (L) channel, which is where most of the integration time goes and where you optimize SNR, detail, etc. And full fill factor (means 100% of the pixels are used) for all three color channels. This is in contrast to a normal DSLR, which has a 50% green and 25% red/blue fill factor, which greatly reduces the sensitivity in those channels.
> 
> The data is still light polluted, however I was a bit surprised at how nice it turned out despite that fact:



You sir, are an inspiration!

Fantastic picture!


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## LordofTackle (Nov 17, 2016)

*WOW,*

Jon, this is just awesome!!


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## StudentOfLight (Nov 17, 2016)

My upload speed is a bit limited at the moment. I'll PM you with a folder once files are uploaded. Thanks for the help.


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## rpt (Nov 18, 2016)

jrista said:


> *Andromeda Galaxy*
> 
> One of my latest images. This is a classic object, but one of the first LRGB images I've made with my new mono camera. Full fill factor for both the luminance (L) channel, which is where most of the integration time goes and where you optimize SNR, detail, etc. And full fill factor (means 100% of the pixels are used) for all three color channels. This is in contrast to a normal DSLR, which has a 50% green and 25% red/blue fill factor, which greatly reduces the sensitivity in those channels.
> 
> The data is still light polluted, however I was a bit surprised at how nice it turned out despite that fact:


Absolutely fantastic!


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## Click (Nov 18, 2016)

Awesome. Beautiful picture.


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## meywd (Nov 18, 2016)

Amazing shot Jon, thanks for sharing.


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## StudentOfLight (Nov 18, 2016)

jrista said:


> I can actually do a full evaluation if you want. It is actually pretty easy. I can evaluate for several different ISOs if you wish.
> 
> What I would need for each ISO setting:
> 
> ...


Here are 80D RAW files for Jon and anyone else interested in doing statistical analysis as discussed above: https://www.dropbox.com/sh/iuei2ks8jjn7pj5/AACjB1Rl9nEiZQYm2HTNGFf3a?dl=0


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## jrista (Nov 18, 2016)

StudentOfLight said:


> My upload speed is a bit limited at the moment. I'll PM you with a folder once files are uploaded. Thanks for the help.



Here are the results for your data. I'm having problems loading the raw data into PixInsight at the moment...it does not seem to be quite up to date to handle 80D files yet, so I may do some additional fiddling to verify these values. In particular, the dynamic range values seem...unreasonably high for the higher ISO settings. That may be due to the fact that the overscan area is not being cropped out properly by PI at the moment, which seems to be giving me improbably high FWC values at each ISO setting. I do believe the read noise, offset and dark current levels are correct, though:

*ISO 100:*
Read Noise: ~6.3e- RMS
Dark Current: ~1.2e-/s
Offset: 128 ADU
FWC: ~139127e- (HIGHLY IMPROBABLE!!)
Gain: 8.4e-/ADU 14-bit
DR: 14.5 stops (HIGHLY IMPROBABLE!!)

*ISO 200:*
Read Noise: ~4.45e- RMS
Dark Current: ~1e-/s
Offset: 128 ADU
FWC: ~72394e- (HIGHLY IMPROBABLE!!)
Gain: 4.4e-/ADU 14-bit
DR: 14 stops (HIGHLY IMPROBABLE!!)

*ISO 400:*
Read Noise: ~3.63e- RMS
Dark Current: ~0.25e-/s
Offset: 512 ADU
FWC: ~36715e- (Improbable)
Gain: 2.25e-/ADU 14-bit
DR: 13.35 stops (Rather Improbable at this ISO)

*ISO 800:*
Read Noise: ~3.3e- RMS
Dark Current: ~0.23e-/s
Offset: 512 ADU
FWC: ~18900e- (Seems improbable)
Gain: 1.155e-/ADU 14-bit
DR: 12.5 stops (Rather Improbable at this ISO)

ISO 1600:
Read Noise: ~2.95e- RMS
Dark Current: ~0.18e-/s
Offset: 512 ADU
FWC: ~9550e- (May be possible, but unlikely for this camera and pixel size)
Gain: 0.583e-/ADU 14-bit
DR: 11.7 stops (Rather improbable at this ISO)

I think the issue may be the flats. Your flat levels seem to be very low...only a couple thousand ADU. Is there any way you can give me more exposed flats? If you can get the histogram to peak around 1/2 histogram for all the flats at each ISO, that should give me better results. 

Another thing that seems to be a bit problematic is, the dark frames don't seem to have a higher level than the bias frames. Even with low dark current (and, based on the numbers I'm getting, the dark current is NOT low), the level of the dark frames should be higher than the level of the bias frames...however, that is not the case. That is resulting in some of the mean differences between darks and biases being negative, which might be contributing to the unrealistically large full well capacities. 

I'll need better data to get you accurate results. For now, disregard the FWC and DR values above...as they are very likely NOT real. (And, well, if they are real...Damn Canon! Way to go!!!)

One thing I did notice. There is DEFINITELY a change in the offset level at ISO 100 and 200. The offset is 128 14-bit ADU until ISO 400, where it changes back to Canon's standard 512 ADU offset, which is also used for all other ISO settings.


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## StudentOfLight (Nov 18, 2016)

I shot all the images under the same indoor ambient conditions. I made sure to turn off all the noise reduction options in the shoot settings menu. The long exposures darks are what they are. Bias frame as well.

The original flats were perhaps a bit too dark. What I'll do is re-shoot the flats with ETTL flash (+0.7EV) at ISO 200, 400, 800, 1600 and 3200. That gives a neat peak in all channels slightly to the right of mid-tone, with no highlight clipping.

They'll take a while to upload due to my internet connection. Apologies for not doing them better the first time round.


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## jrista (Nov 18, 2016)

Alright. Hopefully the flats will do it.

I evaluated the dark frames more deeply. It seems that Canon does indeed employ some kind of dark current offset removal technology. I don't know that I would call it dark current suppression per-se...I would need to evaluate a range of darks across a wide range of temperatures to evaluate that properly. However, it does appear as though any dark current OFFSET _is_ removed by the camera. That means that the only thing that changes in the frames is the dark current noise, and that is definitely evident when comparing a 30s to a 300s dark frame. 

I think there may be interesting implications for dynamic range with such technology. Usually, longer exposures suffer a loss of dynamic range, as the offset increases from dark current. As the offset grows, your dynamic range shrinks. However, if the offset never grows, then you would never lose any dynamic range when doing long exposures. That is quite interesting. The 5D III might have had an early form of that technology. While it did not have a 0 offset difference, the offset with a 600s sub was only slightly more than a 60s sub, while the dark current noise was much greater. Seems Canon has refined the technology.


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## jrista (Nov 19, 2016)

*Pacman Nebula in HSO*

I thought I'd shared this before, but apparently I had not. This is a tri-channel narrow band image, using the HSO mapping (Red=Hydrogen-alpha, Green=Sulfur-II, Blue=Oxygen-III), albeit with a few blending tweaks of my own to produce a more pleasing blend. 

This is about six hours of total integrated exposure time:


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## meywd (Nov 19, 2016)

Very beautiful Jon, thanks for your efforts.


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## StudentOfLight (Nov 19, 2016)

The new flat frames have finished uploading: https://www.dropbox.com/sh/zlv8c2yia1cwvg4/AAAMJlDh8Wn137V7YGqs3LHDa?dl=0


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## rpt (Nov 19, 2016)

meywd said:


> Very beautiful Jon, thanks for your efforts.


+1

GAS is forming...


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## lion rock (Nov 19, 2016)

jrista,
A wonderful shot!
I think I can even see a 3 dimensional quality to part of the photo. It is simply an amazing image.
Thank you for posting.
-r



jrista said:


> *Pacman Nebula in HSO*
> 
> I thought I'd shared this before, but apparently I had not. This is a tri-channel narrow band image, using the HSO mapping (Red=Hydrogen-alpha, Green=Sulfur-II, Blue=Oxygen-III), albeit with a few blending tweaks of my own to produce a more pleasing blend.
> 
> This is about six hours of total integrated exposure time:


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## Click (Nov 19, 2016)

Awesome. Beautiful picture. Well done, Jon.


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## StudentOfLight (Nov 19, 2016)

I must agree with Lion Rock, the best astro images are ones like that where you can really get a sense of depth to the images. Achieving the necessary precision of capturing faint details and maintaining good tonality in highlights and shadows really gives a 3D-look. It takes many hours of dedication and true craftsmanship to create such amazing images. Jon, you are such an inspiration. Thanks for all your input on CR.


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## Valvebounce (Nov 21, 2016)

Hi Jon. 
Absolutely beautiful. Stunning shot. 

Cheers, Graham. 



jrista said:


> *Pacman Nebula in HSO*


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## lion rock (Nov 21, 2016)

StudentofLight,
Thanks for the support. Though I beg to differ on one point:
It takes longer than HOURS of dedication. It would really take years to get to this exquisite state of results. Some of us may take a lifetime and still not get there. I would like to attempt some shots of the night sky, but there is still work that gets IN THE WAY! Sob. 
Jon is really an inspiration.
-r



StudentOfLight said:


> I must agree with Lion Rock, the best astro images are ones like that where you can really get a sense of depth to the images. Achieving the necessary precision of capturing faint details and maintaining good tonality in highlights and shadows really gives a 3D-look. It takes many hours of dedication and true craftsmanship to create such amazing images. Jon, you are such an inspiration. Thanks for all your input on CR.


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## jrista (Nov 21, 2016)

Geez. You guys are going to make my head burst into flames here. 

I really do encourage you guys to explore astrophotography. It is a very challenging hobby, and definitely more work than regular daytime photography (each and every single image I create these days usually involves tens of hours of actual exposure, and tens of hours more post-processing work, sometimes with second and third rounds of processing). It takes definite dedication, good software for processing, and also takes some technical and mathematical prowess, but if you put your mind to it, you can create some amazing images. In the end it can be a very satisfying hobby. Just be prepared to invest some TIME! 

I've seen a number of you pick the hobby up and start creating some great images here just in the last year or so, which is great!


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## East Wind Photography (Nov 24, 2016)

Yes it definitely requires a great deal of time and dedication to get results like Jon has. 

Pixinsight is definitely the tool to master but it takes more than a month to learn the software and unless you have $$$ and time to throw at it, it may not be the best tool for everyone.

The rest of us have to live with mediocrity using free tools like deep sky stacker and post processing tools better suited for weddings and bar mitzvahs. I have tried my best over the years and have realized that I just don't have the time, money, and dedication to throw at it...after all I have teenagers getting ready for college...one of them mentioned law school. 8/. 

While I wait for an automated tool that can get me 75% there, I live with 10% and a lot of unfinished projects. I am resolved to just frequent this forum and eagerly await the latest image that Jon has collected and processed. Hopefully along the way, he will share something that will inspire me to try again and again and again.

I'm disappointed that he has moved away from using a DSLR as that is what the rest of us minions can afford to use in both dollars and time. Seeing images created using monochrome sensors and a plethora of filters is nice but I can see those by visiting NASAs HST site. It's great to see what people are capturing in their backyard using such but it doesn't help me get to my 75% goal and probably not applicable to this CR forum.

I'm hoping to get some time in this weekend if weather permits...maybe I can get to 15%.


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## dcm (Nov 24, 2016)

jrista said:


> Alright. Hopefully the flats will do it.
> 
> I evaluated the dark frames more deeply. It seems that Canon does indeed employ some kind of dark current offset removal technology. I don't know that I would call it dark current suppression per-se...I would need to evaluate a range of darks across a wide range of temperatures to evaluate that properly. However, it does appear as though any dark current OFFSET _is_ removed by the camera. That means that the only thing that changes in the frames is the dark current noise, and that is definitely evident when comparing a 30s to a 300s dark frame.
> 
> I think there may be interesting implications for dynamic range with such technology. Usually, longer exposures suffer a loss of dynamic range, as the offset increases from dark current. As the offset grows, your dynamic range shrinks. However, if the offset never grows, then you would never lose any dynamic range when doing long exposures. That is quite interesting. The 5D III might have had an early form of that technology. While it did not have a 0 offset difference, the offset with a 600s sub was only slightly more than a 60s sub, while the dark current noise was much greater. Seems Canon has refined the technology.



Jon, I'm amazed at the images you produce and may someday try my hand at astro (when I have more time). In the meantime I'll keep learning from your informative posts. 

Now that you've done the 5D IV, would you like to analyze a 1DX II? I posted a set of biases, darks (30s and 300s), and midtone flats for ISO 100 to 25600 at https://www.dropbox.com/sh/rqzzaff4jeu364a/AABRst_qMczLSIS8MNWC-nBia if you are interested. Hopefully I produced them correctly. If not, let me know and I'll make any necessary adjustments.


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## jrista (Nov 24, 2016)

East Wind Photography said:


> Yes it definitely requires a great deal of time and dedication to get results like Jon has.
> 
> Pixinsight is definitely the tool to master but it takes more than a month to learn the software and unless you have $$$ and time to throw at it, it may not be the best tool for everyone.
> 
> ...



The ASI1600MM-Cool camera I use costs a third the price of a 5D IV. With a filter wheel and LRGB filters, it is still less than half the price. With NB filters, it is just over half the price. I'm honestly not sure why you think it costs too much. ;P 

The ASI1600 kit with LRGB fitlers and a filter wheel is $1580. ZWO ships direct, and you could have the camera in your hands within a few days. They also just released some narrow band filters, and are selling the new kit for $1900 on sale right now. That is still less than a 5D IV, less than a 6D even. 

I got this camera because it was significantly cheaper than the CCD alternatives, and had significantly lower noise. I absolutely do not regret it, and it has been far more enjoyable to use IMO.


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## jrista (Nov 24, 2016)

*Heart Nebula - Hubble Palette (SHO)*

This is a bit over 16 hours of total integration on Heart Nebula, in all three primary narrow band channels:

SII: 46x600s (460m)
Ha: 31x600s (310m)
OIII: 20x600s (200m)






Full Size: http://www.astrobin.com/full/273197/B/

This was kind of an afterthought project, as I kept acquiring data on Heart Nebula at the end of the night, and it was never really in the forefront of my mind to really acquire a lot of data on it. Well, now that I finally processed the data, I wish I'd focused on it a bit more. I ended up with over 16 hours of data in total...and the SII and OIII channels could use some more integration. I think I'll try to get both of them up to about 8 hours each, and leave Ha at just 5h20m, to clean up the fainter parts of this image.


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## rpt (Nov 24, 2016)

Wow! Lovely!


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## lion rock (Nov 24, 2016)

Beautifully shot.
Can't believe the universe is so colourful, have to take a trip there one of these days! 8) : ;D ;D
-r



jrista said:


> *Heart Nebula - Hubble Palette (SHO)*
> 
> This is a bit over 16 hours of total integration on Heart Nebula, in all three primary narrow band channels:
> 
> ...


----------



## jrista (Nov 24, 2016)

Thanks, guys!

The universe is an amazing place...however, it isn't quite that colorful. This is the Hubble palette, and is false color mostly. I mapped very specific wavelengths to red, green, and blue. Thing is, in reality, most of the light is red, just of slightly different red wavelengths (hydrogen and sulfur), and some of it is a more blue green-blue color (oxygen). The oxygen is usually more diffuse and tenuous and cloudy, so it in reality it is not as visible as I've made it here. 

This is a more realistic representation:






The hydrogen gas dominates, with sulfur wreathed underneath it, and the oxygen drifting among the bright red gasses as a fainter emission.


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## StudentOfLight (Nov 24, 2016)

"Incroyable!" 

Pardon my French.

It's beautiful :'(


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## Click (Nov 24, 2016)

Awesome. Beautiful pictures. Well done, Jon.


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## LordofTackle (Nov 25, 2016)

Really awesome pictures Jon!! 
I would be glad if I could ever produce pictures such as your "afterthoughts"


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## East Wind Photography (Nov 27, 2016)

Using the 1dxii tonight. Finished a series of the pleides at iso1600. Tested one shot of m31 at iso3200 and really impressed with the noise visually. Running 40 subs as i type. Im tempted to make a short run 20 subs at iso 6400. Im using my 300mm at f2.8 and taking 45 second shots.

M31 right now is at the zenith and in the darkest park of my sky.


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## rpt (Nov 27, 2016)

Look forward to the pictures


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## jrista (Nov 29, 2016)

I am looking forward to them as well.

One thing about high ISO on Canon cameras. Beyond a certain ISO (usually ISO 1600) a secondary downstream amp kicks in, which flattens the read noise curve. Make sure that using ISO 3200 and 6400 is really giving you the benefit of usefully lower read noise than ISO 1600. Based on my experience across all of the cameras I have tested, using ISO's above 3200 primarily results in loss of DR and not much improvement in terms of read noise. You are likely better off at ISO 1600.


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## telemaq76 (Nov 30, 2016)

agree iso is not that important in astrophotography, only exposure time is important to collect data

here is the rosetta nebula
28x4 minutes h-alpha iso-800 f4 with canon 700da+500f4is+neq6 pro
Iris+photoshop
i blended it to a color file i took last year


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## Click (Nov 30, 2016)

Awesome. Beautiful shot. Well done, telemaq76.


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## Hector1970 (Nov 30, 2016)

Hi Jon, as usual I'm awestruck by your pictures. I've been obsessed With space since childhood. Buck Rogers in the 25th century , Battlestar Galactica and Star Trek were staple TV watching when I was young.
I was wondering if you could recommend two types of beginner set ups.
a ) Using a Canon camera and lens
b) A more specific to Astro set up.
I've done the Milky Way and the moon but I'd love to go a bit deeper into space.
Weather conditions frequent clouds would be against me but I'd love to give it a go.
Would there be any beginners guide you'd recommend.
I get lost in the technology and tools used.
I have a 70-200 F2.5 and a 100-400 II - could I see something interesting with them?


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## Don Haines (Nov 30, 2016)

telemaq76 said:


> agree iso is not that important in astrophotography, only exposure time is important to collect data
> 
> here is the rosetta nebula
> 28x4 minutes h-alpha iso-800 f4 with canon 700da+500f4is+neq6 pro
> ...


fantastic!


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## StudentOfLight (Nov 30, 2016)

Excellent Telemaq!

Is it a mostly IR or does it just take extremely deep exposures to get good detail on rosette?


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## LordofTackle (Nov 30, 2016)

Hector1970 said:


> Hi Jon, as usual I'm awestruck by your pictures. I've been obsessed With space since childhood. Buck Rogers in the 25th century , Battlestar Galactica and Star Trek were staple TV watching when I was young.
> I was wondering if you could recommend two types of beginner set ups.
> a ) Using a Canon camera and lens
> b) A more specific to Astro set up.
> ...



+1


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## StudentOfLight (Nov 30, 2016)

My first attempt at Orion with the 80D. Sometimes my exposure is slightly too long and there is a bit of trailing and stars become oval. In this case movement was from bottom right to top left. What is a good method for deconvolution? 



Orion, De Mairan and Running-Man Nebulae by Omesh Singh, on Flickr


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## Don Haines (Nov 30, 2016)

StudentOfLight said:


> My first attempt at Orion with the 80D. Sometimes my exposure is slightly too long and there is a bit of trailing and stars become oval. In this case movement was from bottom right to top left. What is a good method to deconvolve?


First Attempt? NOT BAD!

So how did you do it and what software?


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## Click (Nov 30, 2016)

StudentOfLight said:


> My first attempt at Orion with the 80D...



Nicely done, StudentOfLight.


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## StudentOfLight (Nov 30, 2016)

Don Haines said:


> StudentOfLight said:
> 
> 
> > My first attempt at Orion with the 80D. Sometimes my exposure is slightly too long and there is a bit of trailing and stars become oval. In this case movement was from bottom right to top left. What is a good method to deconvolve?
> ...


395-Light, 55-Dark, 69-Offset, 18-Flat
Stacked in DeepSkyStacker (2x drizzle)
Set DSS Output as 16-bit TIF
Imported into Lightroom 6
Created virtual copy, edited original as Bright-detail exposure and the other as Dark-detail exposure
Exported exposures as JPGs
Blended final image in GIMP

The shadows are a bit noisier than I'd prefer, but I did push the exposure 9 stops (in the bright exposure) in order to bring out some detail in the loop on top of Orion Nebula and the dust around Running Man.


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## rpt (Dec 1, 2016)

What do you guys set the white balance to?


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## StudentOfLight (Dec 1, 2016)

rpt said:


> What do you guys set the white balance to?


During Capture I use something in the 3800-4200K range but since I'm shooting RAW don't think it really matters. In editing there is no silver bullet as light pollution varies from place to place: http://www.canonrumors.com/forum/index.php?topic=20392.msg623763#msg623763


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## rpt (Dec 1, 2016)

StudentOfLight said:


> rpt said:
> 
> 
> > What do you guys set the white balance to?
> ...


Cool! Thanks.


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## StudentOfLight (Dec 1, 2016)

Keyhole Nebula in Carina: 214xLight 55xDark 69xBias 18xflat

Carina was still quite low to the horizon, so not ideal to shoot at the moment but light pollution and humidity were relatively low so I reckoned, what the heck, since I'm out here already give it 10minutes. The 80D shot with 2x drizzle is very similar in detail and clarity to what I got with the 6D with 3x drizzle. Interestingly my 6D shot of Carina used 43minutes of exposure while the 80D was about 9minutes. Goes to show how important dark sky is. Hopefully I can get good conditions in the next couple months when it is higher in the sky.



Keyhole Nebula in Carina by Omesh Singh, on Flickr


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## Don Haines (Dec 2, 2016)

StudentOfLight said:


> rpt said:
> 
> 
> > What do you guys set the white balance to?
> ...



I am very lucky as I am fairly close to Algonquin Park, Ontario, and it has very dark skies. I made three trips there this summer with camera, tripod, and motorized mount..... but unfortunately it was cloudy for one trip and rained the other two.... oh well, next year 

Another dark area in Eastern Ontario is Frontenac park. Unfortunately, my camping spot did not have a good view of the sky and the clouds came in shortly after sunset, but I did manage to wade out into the lake and get this snap of the Milky Way...


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## Click (Dec 2, 2016)

Nice picture, Don. Well done.


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## Don Haines (Dec 2, 2016)

My question is about filters.

My home is far enough out of town that the night sky is visible, but there is still some light pollution. Is there a filter (preferably 77mm) that I can use to help cope with the light pollution?


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## telemaq76 (Dec 2, 2016)

31x4 minutes filtre cls-ccd
18x4 minutes filtre h-alpha 6nm, no time for more
25 darks, 1000 offsets, 15 flats
avec un canon 700d astrodon, lens canon 500 f4Is on mount Skywatcher neq6pro
only 18 exposures then it s still noisy and it s a bit cropped


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## jrista (Dec 2, 2016)

Don Haines said:


> My question is about filters.
> 
> My home is far enough out of town that the night sky is visible, but there is still some light pollution. Is there a filter (preferably 77mm) that I can use to help cope with the light pollution?



Any LP filtration will likely just diminish the quality of your results. There is always LP. In fact, airglow, natural light pollution from the ionizing layers of our atmosphere, imposes the upper limit on sky darkness at around 22-22.5mag/sq". Once you get out about half way into a yellow bortle zone or darker (you can look up maps for the scale), then LP filtration really hurts more than it helps, as it tends to decimate color fidelity. 

If you are in an orange, red, or white zone, an IDAS LPS-D1 can help, although I don't think you'll ever find one in 77mm size. You might have to step down to a smaller one.


----------



## Don Haines (Dec 2, 2016)

jrista said:


> Don Haines said:
> 
> 
> > My question is about filters.
> ...


I'm in a light green area.... I guess that means just use the bare lens.... Thanks.


----------



## chrysoberyl (Dec 2, 2016)

StudentOfLight said:


> My first attempt at Orion with the 80D. Sometimes my exposure is slightly too long and there is a bit of trailing and stars become oval. In this case movement was from bottom right to top left. What is a good method for deconvolution?



Nice first shot! No tracker? I have an 80D and a 70-200, but I was convinced I would have to use a tracker.

If you didn't use a tracker, I may have to consider my 80D + the Samyang 85mm 1.2 (when it becomes available, if coma is low, etc., etc.) for intermediate sky astro.


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## StudentOfLight (Dec 3, 2016)

chrysoberyl said:


> StudentOfLight said:
> 
> 
> > My first attempt at Orion with the 80D. Sometimes my exposure is slightly too long and there is a bit of trailing and stars become oval. In this case movement was from bottom right to top left. What is a good method for deconvolution?
> ...


If you have a tracker then you don't have to shoot hundreds of exposures (so less wear and tear) and less processing time. Also when you track you will capture more faint details than possible with multiple short exposures. What happens with multiple short exposures is that the faint subjects will not supply enough light to raise them above the noise floor, so they will be averaged out in the stacking process. At least that is how I understand things.

If you can afford (or have the ingenuity and time to build) a tracking system then it will be incredibly beneficial.


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## telemaq76 (Dec 7, 2016)

Ic 11 the pac man nebula
rvb 19 poses de 3minutes30 +15 darks+15 flats+1000 offsets
h-alpha 37 x 4 minutes + 17 darks + 15 flats + 1000 offsets


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## Click (Dec 7, 2016)

Beautiful picture. Well done, telemaq76.


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## chrysoberyl (Dec 8, 2016)

StudentOfLight said:


> Keyhole Nebula in Carina: 214xLight 55xDark 69xBias 18xflat
> 
> Carina was still quite low to the horizon, so not ideal to shoot at the moment but light pollution and humidity were relatively low so I reckoned, what the heck, since I'm out here already give it 10minutes. The 80D shot with 2x drizzle is very similar in detail and clarity to what I got with the 6D with 3x drizzle. Interestingly my 6D shot of Carina used 43minutes of exposure while the 80D was about 9minutes. Goes to show how important dark sky is. Hopefully I can get good conditions in the next couple months when it is higher in the sky.



What's drizzle?


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## StudentOfLight (Dec 8, 2016)

chrysoberyl said:


> StudentOfLight said:
> 
> 
> > Keyhole Nebula in Carina: 214xLight 55xDark 69xBias 18xflat
> ...


It is a setting in DeepSkyStacker. 

As I understand it, it scales up your subs by a factor before stacking them. So it will result in a higher resolution output file. DSS is a 32bit program so your computer the program can run out of memory and crash if you use drizzle without selecting a specific crop area.

In order to use drizzle you will need to select one of the exposures as a reference and apply a crop (otherwise DSS will crash because of running out of memory) The Drizzle option is either 2x or 3x drizzle. Depending on your stacking parameters it might temporarily require quite a bit of free hard drive space as well during the stacking process.

Here are a couple of screenshots from DSS:


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## jrista (Dec 10, 2016)

Drizzle doesn't really scale the data up before stacking. Drizzle is a means by which you actually gain true resolution due to the way the information from all the subs is combined, assuming the data was undersampled and also properly dithered (dithering is critical for drizzling to work). It is a form of superresolution, which can potentially allow you to resolve information beyond the diffraction limit of the lens, and certainly beyond the limit of seeing. 

The actual algorithm's mechanism is actually somewhat complex, so I won't go into it here. Suffice it to say, if you are undersampled (which is usually the case with the average DSLR pixel size and camera lenses or short refractors), you can get much cleaner data, rounder stars, smaller stars, and more detail if you drizzle. Also note that this is not only an option in DSS. It is an algorithm originally designed by for scientific purposes, and has been utilized by the Hubble team to increase resolution with some of the imager data from the Hubble telescope (although they tend to be significantly more precise in their dithering, down to the exact pixel level.)


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## telemaq76 (Dec 10, 2016)

i just tried my first drizzle this mornin with old images of M51. Some pictures i took with 1000mm focale length, 
my canon 500f4 and a teleconverter X2. I m pretty happy with the result. 
40x180 sec f8 iso-800
49 dark
DSS with drizzle 3x


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## jrista (Dec 10, 2016)

Nice work! M51 is a tough object...smallish, pretty distant. 


Regarding drizzle, when you dither well and use enough frames, this is the kind of improvement you can get vs. a normal integration:


----------



## Don Haines (Dec 10, 2016)

telemaq76 said:


> i just tried my first drizzle this mornin with old images of M51. Some pictures i took with 1000mm focale length,
> my canon 500f4 and a teleconverter X2. I m pretty happy with the result.
> 40x180 sec f8 iso-800
> 49 dark
> DSS with drizzle 3x



Nice!


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## StudentOfLight (Dec 10, 2016)

jrista said:


> Drizzle doesn't really scale the data up before stacking. Drizzle is a means by which you actually gain true resolution due to the way the information from all the subs is combined, assuming the data was *undersampled* and also properly dithered (*dithering is critical for drizzling to work*). It is a form of superresolution, which can potentially allow you to resolve information beyond the diffraction limit of the lens, and certainly beyond the limit of seeing.
> 
> The actual algorithm's mechanism is actually somewhat complex, so I won't go into it here. Suffice it to say, if you are undersampled (which is usually the case with the average DSLR pixel size and camera lenses or short refractors), you can get much cleaner data, rounder stars, smaller stars, and more detail if you drizzle. Also note that this is not only an option in DSS. It is an algorithm originally designed by for scientific purposes, and has been utilized by the Hubble team to increase resolution with some of the imager data from the Hubble telescope (although they tend to be significantly more precise in their dithering, down to the exact pixel level.)


I was speaking under correction so thanks for the clarification. Astrophotography is a huge investment in time, storage and processing, and it helps to do things the best way that we can to maximize on that investment.

When you say undersampling do you mean shorter exposures or where cropping is required or something else? Also could you please elaborate on dithering. I've tried reading up on these subjects but the wiki pages I found appear to be framed more in terms of audio and so it's hard to connect to imaging, at least to me it is. :-[


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## StudentOfLight (Dec 10, 2016)

telemaq76 said:


> i just tried my first drizzle this mornin with old images of M51. Some pictures i took with 1000mm focale length,
> my canon 500f4 and a teleconverter X2. I m pretty happy with the result.
> 40x180 sec f8 iso-800
> 49 dark
> DSS with drizzle 3x


This is one of the deep sky objects that makes me jealous of you Northern Hemisphere guys. It barely creeps above the horizon here :'(


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## alexthegreek (Dec 13, 2016)

In DSS you get 2 options for drizzle.One is in the "raw setings" menu as a way to avoid interpolation and you need to dither (it is the one jrista is talking about).The other is in the stacking parameters menu and is the one that produces a larger size image so I believe you are talking about two different things but Im no guru anyway!Well...here's my Pleiades (500d 43x1min iso 800 + about 50 darks + 100 bias using a Jupiter 200mm at f5.6).Notice the almost absent color and the bad star quality!hahaha!!


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## StudentOfLight (Dec 18, 2016)

I reprocessed my earlier Orion pic to bring out more dust details. 

The deep shadows are a bit grainy, but next time I'll get a deeper exposure and they should be cleaner.



Orion (Reprocessed) by Omesh Singh, on Flickr


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## Click (Dec 18, 2016)

Very nice picture, StudentOfLight.


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## StudentOfLight (Dec 18, 2016)

Thanks Click. I'm looking forward to the next couple of months when these objects will be higher in the sky. Hopefully I'll get some good weather and I'll have a better go at them.


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## StudentOfLight (Dec 20, 2016)

Carina OB1 Association by Omesh Singh, on Flickr


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## Click (Dec 20, 2016)

Awesome. I really like this picture. 

Well done, StudentOfLight.


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## StudentOfLight (Dec 20, 2016)

Thanks Click. I have a love affair with the Carina Nebula.

Just out of interest, here is a comparison illustrating the difference in apparent size between Carina and Orion. Now on top of that consider that Carina is six times further away than Orion...


----------



## jrista (Dec 20, 2016)

StudentOfLight said:


> Thanks Click. I have a love affair with the Carina Nebula.
> 
> Just out of interest, here is a comparison illustrating the difference in apparent size between Carina and Orion. Now on top of that consider that Carina is six times further away than Orion...



Carina is massive. It isn't really a nebula like Orion, it is a full blown molecular cloud and HII region. It is significantly larger than the Orion Nebula in real terms.


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## alexthegreek (Dec 23, 2016)

I have a question about exposure, when we say the histogram should have a seperation from the left part we do mean each individual channel right?Not the luminance histogram.Also i've been trying to image the heart and soul nebulas which are not visible in a single exposure.I tried magic lantern's display gain in conjuction with liveview fps override but it wasn't enough.Any tricks I can do?I'm going out only with my dslr and star adventurer so no laptops or anything.I guess the only solution is a goto mount!


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## East Wind Photography (Dec 29, 2016)

alexthegreek said:


> I have a question about exposure, when we say the histogram should have a seperation from the left part we do mean each individual channel right?Not the luminance histogram.Also i've been trying to image the heart and soul nebulas which are not visible in a single exposure.I tried magic lantern's display gain in conjuction with liveview fps override but it wasn't enough.Any tricks I can do?I'm going out only with my dslr and star adventurer so no laptops or anything.I guess the only solution is a goto mount!



So if you are in a good dark sky site and shooting really low light emission nebula, you will need to increase your iso above normal levels above iso 1600 when using the star adventurer. Ive used that mount quite a bit and you are pretty limited to exposures of less than 60 seconds. If you dont care that much for perfect stars, you can go a bit longer. However the only way is to use a higher iso to record more light and just live with the noise until you can get a better mount. There is a pretty consistent increase in the cost of the gear vs the reduction of noise in the final image. If your budget is limited then you do what you can. The goal is to record the image and then figure out what you need to do to improve it.


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## telemaq76 (Dec 30, 2016)

finally a clear sky after one month waiting, i tried a new target, ngc 2174 in orion constellation
23x4 min for colors and 12x4 minutes for h-alpha....i took lots more then i realized my lens was ice covered, after maybe one hour of shooting. then i kept only 12 subs for h-alpha


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## rpt (Dec 30, 2016)

This is lovely!


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## Click (Dec 30, 2016)

Beautiful. Well done, telemaq76.


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## rpt (Jan 1, 2017)

telemaq76 said:


> finally a clear sky after one month waiting, i tried a new target, ngc 2174 in orion constellation
> 23x4 min for colors and 12x4 minutes for h-alpha....i took lots more then i realized my lens was ice covered, after maybe one hour of shooting. then i kept only 12 subs for h-alpha


I see faces in that.

Happy new year all!


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## telemaq76 (Jan 3, 2017)

in my opinion the best scenic view in the sky





i added 19*4 min incolor to my previous 25*4 h-alpha pictures, iso-800 f4
with my canon 500 f4, canon 700da+neq6pro


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## Click (Jan 3, 2017)

Stunning. Great picture, telemaq76. Well done.


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## NorbR (Jan 3, 2017)

telemaq76 said:


> in my opinion the best scenic view in the sky



Fantastic picture telemaq76, thanks for sharing !

I've said it before but I'll say it again, this whole thread is awesome, I never miss a post. So thanks to everybody who contributes to the show


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## scyrene (Jan 15, 2017)

Finally I have something I don't feel too embarrassed to post. Here's my Orion Nebula...

This is a shade under 90 minutes' integration. Actually it's an unorthodox combination of 400mm and 500mm shots, as the Affinity stacking is pretty good at lining things up and rescaling. I started at 400mm (the 70-200 + 2x), then tentatively tried my 500 on the same mount, which worked fine.

I got the Star Adventurer, and it seems mostly what I wanted: easy and quick to set up, and with the weight capacity I needed. It's not go-to, but my go-to mount rarely went-to where I wanted anyhow, I never could figure out why.

80x30secs + 81x25secs both at 400mm, and 62x15secs at 500mm with an Astronomik LP filter (which fits in the 500L's drop-in filter), all ISO 3200 I think (all wide open, so f/5.6 and f/4 respectively). Preprocessed in Lightroom, stacked and normalised in Affinity, finished back in Lr.

We only get one clear night in maybe two weeks here, so it'll be slow progress, but I do still love it.


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## Click (Jan 15, 2017)

Nice picture. Well done, scyrene.


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## scyrene (Jan 19, 2017)

Click said:


> Nice picture. Well done, scyrene.



Thanks as always, Click


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## telemaq76 (Jan 19, 2017)

mosaic of 2 pictures done with 500mm

32x4 min for each in h-alpha


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## Click (Jan 19, 2017)

Very nice B&W picture, telemaq76.


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## rpt (Jan 20, 2017)

Click said:


> Nice picture. Well done, scyrene.


+1


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## rpt (Jan 20, 2017)

Click said:


> Very nice B&W picture, telemaq76.


Nice!


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## alexthegreek (Jan 25, 2017)

Hi fellas!Of these 2 light pollution maps, which one do you think is more reliable?http://darksitefinder.com/maps/world.html or https://www.lightpollutionmap.info ?


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## jrista (Jan 27, 2017)

alexthegreek said:


> Hi fellas!Of these 2 light pollution maps, which one do you think is more reliable?http://darksitefinder.com/maps/world.html or https://www.lightpollutionmap.info ?



The former is a Bortle Scale map. The bortle scale is a simple way to gauge site darkness based on visual cues. Great for visual, but if you aim for a Bortle blue or darker you could be driving for hours before you get to the dark site, and for imaging you don't necessarily need to go that far.

The latter is a map based on actual satellite measurements of light emissions from the ground. It is VASTLY more accurate than the Bortle scale, and while it may not help you find the best visual observing dark sites, anything on the latter map that is cyan or darker is usually EXCELLENT for imaging. Green is good for imaging. Anything yellow through red is poor for imaging.


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## alexthegreek (Jan 27, 2017)

[/quote]

The former is a Bortle Scale map. The bortle scale is a simple way to gauge site darkness based on visual cues. Great for visual, but if you aim for a Bortle blue or darker you could be driving for hours before you get to the dark site, and for imaging you don't necessarily need to go that far.

The latter is a map based on actual satellite measurements of light emissions from the ground. It is VASTLY more accurate than the Bortle scale, and while it may not help you find the best visual observing dark sites, anything on the latter map that is cyan or darker is usually EXCELLENT for imaging. Green is good for imaging. Anything yellow through red is poor for imaging.
[/quote]

Thanks for the reply jrista!It just seemed very optimistic (looking at the latter map) that I live in a red area and a cyan or even better area is just 20-30 min drive!


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## telemaq76 (Feb 21, 2017)

a try on ic443, not an easy target





63*3 minutes +23 darks, + flats and offsets
canon 700da+500f4 is+neq6pro


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## Click (Feb 21, 2017)

Very nice B&W. Well done, telemaq76.


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## chrysoberyl (Feb 21, 2017)

telemaq76 said:


> a try on ic443, not an easy target
> 
> 63*3 minutes +23 darks, + flats and offsets
> canon 700da+500f4 is+neq6pro



Nice clouds! Thanks for your inspiring posts.


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## JOSH1992 (Feb 23, 2017)

Mesmerizing photos !! Loving them


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## East Wind Photography (Feb 26, 2017)

Jon i have been circling back around and working on comets again using the new subtraction functions within the comet align module. I still need a comet integration to subtract from the lights but ending up with faint trails in the comet integration image. Actually windsor sigma is removing the stars but there are halos i guess that are not being removed and are showing up everywhere.

Whats the best way of getting rid of these? They end up in the comet tails and so cloning is not very effective.



jrista said:


> East Wind Photography said:
> 
> 
> > jrista said:
> ...


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## telemaq76 (Apr 21, 2017)

long time nobody posted anything
here is ngc 4565, 35*600sec with 21 darks, flats and 200 offsets


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## chrysoberyl (Apr 21, 2017)

telemaq76 said:


> long time nobody posted anything
> here is ngc 4565, 35*600sec with 21 darks, flats and 200 offsets



Thank you. Is that a protostar?

Binged it - a galaxy with a central bulge. Very nice shot!


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## Click (Apr 21, 2017)

Very nice picture, telemaq76. 8)


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## rpt (Apr 21, 2017)

Click said:


> Very nice picture, telemaq76. 8)



Lovely picture telemaq76!


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## scyrene (Apr 21, 2017)

telemaq76 said:


> long time nobody posted anything
> here is ngc 4565, 35*600sec with 21 darks, flats and 200 offsets



Lovely work


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## telemaq76 (Apr 24, 2017)

thank you guys !


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## telemaq76 (May 28, 2017)

M16, the eagle nebula, 6 hours integration time, 36*10 min
with canon 700da, canon 500 f4 is and neq6pro
autoguiding with asi120
software iris then photoshop


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## Click (May 28, 2017)

Beautiful shot. Well done, telemaq76.


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## alexthegreek (Jun 4, 2017)

Hi guys this is alex with another noob question...I hope you enjoy this one...
Milky way season has started so I had my first shooting with a tracker.It went great exept that 
as the galaxy rotated, light polution low at the horizon crept in from the bottom right.The galaxy 
has the framing I wanted but the light polution is tilted.Any solutions to that?Post or while shooting?
Here's the image


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## rfdesigner (Jun 4, 2017)

alexthegreek said:


> Hi guys this is alex with another noob question...I hope you enjoy this one...
> Milky way season has started so I had my first shooting with a tracker.It went great exept that
> as the galaxy rotated, light polution low at the horizon crept in from the bottom right.The galaxy
> has the framing I wanted but the light polution is tilted.Any solutions to that?Post or while shooting?
> Here's the image



nice shot, light pollution is par for the course.. you can get a clip in filter for the DSLR such as

http://www.rothervalleyoptics.co.uk/astronomik-cls-ccd-deep-sky-light-pollution-filter-canon-eos-clip-fit.html

(not connection, just googled clip in light polliution filters, I knew they were out there)

There are various programs that do a good job removing things like this. I still use IRIS which is a nightmare to learn. I've tried photoshop but if you care about reality in your astro shots (I do) then it really feels like cheating (IRIS is good at getting a real data, rather than pretty pictures). Pixinsight is very good and when my scope gets back up and running will be what I migrate to for the pretty stuff.


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## alexthegreek (Jun 5, 2017)

thanks for taking the time to reply rfdesigner
unfortunately I can not use the clip on filters as they are not ef-s compatible and my lenses are all ef-s.The image I posted is a not the final but a quick stretch to show the problem and it will be used as a background for a composite.To be honest I don't mind the LP near the horizon for landscape astro stuff but my problem is the tilt


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## telemaq76 (Jun 6, 2017)

M17 nebula in h-alpha
20x600 sec subs
+dark, flat, offset
canon 700da+500f4is+neq6pro
autoguiding


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## Click (Jun 6, 2017)

Nicely done, telemaq76.


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## weixing (Jun 6, 2017)

Hi,
Look really different from visual and shorter exposure image... the swan is gone. 

Have a nice day.


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## chrysoberyl (Jun 10, 2017)

telemaq76 said:


> M17 nebula in h-alpha
> 20x600 sec subs
> +dark, flat, offset
> canon 700da+500f4is+neq6pro
> autoguiding



Yet another 'clearly hacked into the Hubble feed' shot. Thank you for showing the enormity and beauty of the universe.


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## telemaq76 (Jun 16, 2017)

my first picture made from a video, with a small camera asi120 on my canon 500f4+tc1.4 III


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## Click (Jun 16, 2017)

Very nice moon shot. Well done, telemaq76.


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## telemaq76 (Jun 16, 2017)

thank you click, those small planetary camera are great


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## scyrene (Jun 17, 2017)

telemaq76 said:


> my first picture made from a video, with a small camera asi120 on my canon 500f4+tc1.4 III



Fab! How did you mount that camera to the lens? Are there adaptors available? I tried the other way, mounting a DSLR onto a telescope, but the results were inferior (mostly because I was limited to HD video with no 1:1 magnification on the sensor).


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## telemaq76 (Jun 17, 2017)

yes a 45 euros adaptator, canon ef lens to asi camera works only with Ef lens, not efs. 
the asi120 is a 170$ camera, the sensor is so small, the crop is huge .


----------



## scyrene (Jun 18, 2017)

telemaq76 said:


> yes a 45 euros adaptator, canon ef lens to asi camera works only with Ef lens, not efs.
> the asi120 is a 170$ camera, the sensor is so small, the crop is huge .



Excellent, thanks!


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## telemaq76 (Jun 19, 2017)

new target for me, sh2-54, a nice nebula just over M16
39x600 sec subs in h-alpha


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## Click (Jun 19, 2017)

Another very nice shot. Well done, telemaq76.


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## scyrene (Jun 20, 2017)

telemaq76 said:


> yes a 45 euros adaptator, canon ef lens to asi camera works only with Ef lens, not efs.
> the asi120 is a 170$ camera, the sensor is so small, the crop is huge .



PS - and apologies if you've mentioned this elsewhere in the thread - how are you tracking your targets? I've not yet found a mount that worked easily for me :/


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## telemaq76 (Jun 20, 2017)

yes sure i use a skywatcher neq6pro to track my targets


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## telemaq76 (Jul 10, 2017)

the M8 laguna, very low on horizon, bad seeing
with canon 700da+ 500f4is


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## Click (Jul 10, 2017)

telemaq76 said:


> the M8 laguna, very low on horizon, bad seeing
> with canon 700da+ 500f4is




Beautiful. Well done, telemaq76.


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## scyrene (Jul 27, 2017)

I feel a little embarrassed about posting this, but I think it illustrates that one doesn't need specialist equipment to do deep sky astrophotography.

This is a section towards the core of the Milky Way, centred on Scutum (just above Sagittarius). Fixed tripod, no tracking, no filtering. The 100L macro lens wide open. A panorama of four stacks of 18-27 shots at 10 seconds each, ISO 4000. So not a huge amount of data, pushed to the max.

It's always a race up here, the galactic core only rises in summer, when there's precious little darkness. I'll try for something more official, using my tracking mount, if I get chance, but all the same - I'm amazed how much detail can be pulled out of a sky that appeared featureless and dark to the eye.

Some banding, colour imbalance, due to the camera and the different sky conditions on different nights.


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## telemaq76 (Jul 30, 2017)

nice pano, especially with only 10 sec exposures. With a skytracker and 1 or 3 minutes exposure it will be super awesome. you must have a good sky to see the core like that. 


2 hours around sadr with canon 500f4 is and canon 700da
25*2 min subs + 11 darks, flats and offset


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## Click (Jul 30, 2017)

Beautiful picture, telemaq76.


----------



## james75 (Jul 30, 2017)

telemaq76 said:


> nice pano, especially with only 10 sec exposures. With a skytracker and 1 or 3 minutes exposure it will be super awesome. you must have a good sky to see the core like that.
> 
> 
> 2 hours around sadr with canon 500f4 is and canon 700da
> 25*2 min subs + 11 darks, flats and offset




Beautiful photos! Thanks for sharing.


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## alexthegreek (Aug 28, 2017)

can someone enlighten me about https://www.lightpollutionmap.info ?There's VIIRS 2017 and now a new option, ATLAS 2015, and there's a big difference.Places that are in cyan/dark cyan in viirs are orange in atlas.I know viirs is about light sources and atlas is about light polution at the zenith (which I consider more relevant for imaging).Which one do you use?


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## basketballfreak6 (Jan 11, 2018)

Orion Wide by Tony, on Flickr


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## Click (Jan 11, 2018)

Great shot, Tony.


----------



## gruhl28 (Jan 11, 2018)

Gorgeous


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## basketballfreak6 (Jan 11, 2018)

Click said:


> Great shot, Tony.





gruhl28 said:


> Gorgeous



thanks guys


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## basketballfreak6 (Jan 23, 2018)

testing out new software...short version is shut up and take my money

crop of wide field Orion (to just Horsehead and Flame)



Horsehead Nebula Reprocessed by Tony, on Flickr


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## Handrews (Jan 23, 2018)

Amazing work, Tony!
Would it be possible to share some details?
Regards,
Andrei


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## basketballfreak6 (Jan 23, 2018)

Handrews said:


> Amazing work, Tony!
> Would it be possible to share some details?
> Regards,
> Andrei



thanks Andrei!

yes silly me forgot the deets

heavy crop of wide field Orion (760D mod + 70-200L II @200mm), ~200 lights 30sec f/2.8 ISO1600, shot in bortle 5-6 sky (suburban backyard)

currently playing around with the Astro Pixel Processor, from what i read seems to do a fair bit of what PI does but more intuitive (and frankly i agree considering what a noob like me could get out of it already), it has light pollution/gradient removal which seems very similar to PI's DBE among few other things (some people are saying it's ability to do mosaic is easier and better than PI)

i think the software is only about 6 months old so the developer is still adding things to it (he responded to me that he's planning to add things like star reduction and what not in the future) from what i've seen so far does amazing job for integration then light pollution removal and colour correction, before moving over to like PS/LR to finish off the edits

my few days use so far i feel like this is a great software for people that wants some of the things that PI does but don't have the time or dedication to learn PI properly

hope that helps


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## Click (Jan 23, 2018)

basketballfreak6 said:


> testing out new software...short version is shut up and take my money
> 
> crop of wide field Orion (to just Horsehead and Flame)




Awesome. Beautiful picture.


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## Handrews (Jan 29, 2018)

Many thanks for the details, Tony, much appreciated!


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## Hector1970 (Feb 6, 2018)

I find this Deep Sky Astrophotography amazing.
I live in a country with alot of cloud cover and rain so I think its difficult to get into this genre.
(I think it would be easier to learn if you were more guaranteed clear skies).
At some point everyone is a beginner.
The level of knowledge of techinique, gear and processing abilities appears to be quite high.
I've done wide field astrophotography (Milky Way) and the Northern Lights and star trails but nothing Deepsky.
Alot of the books written seem to be a few years old (they may still be valid).
Any suggestions where to start?
I have most of the photographic gear required (camera, lens, tripods) but not an up to date guider or others pieces of equipment required or the know how to do it.
Are there any good tutorials on the topic?


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## TheJock (Feb 8, 2018)

Has any of the incredible Astro specialists on here had a look for Mr Musk's space-borne Tesla vehicle???


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## hne (Feb 8, 2018)

Stewart K said:


> Has any of the incredible Astro specialists on here had a look for Mr Musk's space-borne Tesla vehicle???



The car is moving away from earth at a speed that is most usefully measured in kilometers/second. Since it was launched a day or so ago, it'll be only a couple thousands of an arc second by now. If you are lucky enough to find the direction with a 1200mm lens on a 24MPx APS-C camera, you could catch it as about 1% of a pixel wide.

The ISS is a different story since it is using one of the lowest possible earth orbits and is more than 100 meter wide in its longest dimension. Looking for that you could easilly get dozens of pixels on the target if you know where to aim: https://www.cloudynights.com/topic/437901-images-of-international-space-station-moon-transit/#entry5654989


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## basketballfreak6 (May 23, 2018)

pretty happy with only 1 hour worth of data



Antares, Rho Ophiuchi and Blue Horsehead by Tony, on Flickr


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## Click (May 23, 2018)

Beautiful shot, basketballfreak6.


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## basketballfreak6 (May 23, 2018)

Click said:


> Beautiful shot, basketballfreak6.



thanks Click!


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## razashaikh (Jun 5, 2018)

basketballfreak6 said:


> pretty happy with only 1 hour worth of data
> 
> 
> 
> Antares, Rho Ophiuchi and Blue Horsehead by Tony, on Flickr


Lovely Shot!


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## basketballfreak6 (Jun 19, 2018)

razashaikh said:


> Lovely Shot!



thanks mate!

Antares again but with longer lens and this time shot from light polluted suburban backyard instead of a dark site! really happy with how it turned out with not even 1 hour's worth of data!



Antares &amp; Rho Ophiuchi by Tony, on Flickr


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## Click (Jun 19, 2018)

Stunning picture. Well done, basketballfreak6.


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## telemaq76 (Jun 21, 2018)

stunning that last one


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## basketballfreak6 (Jun 21, 2018)

Click said:


> Stunning picture. Well done, basketballfreak6.





telemaq76 said:


> stunning that last one



thanks guys!


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## razashaikh (Jun 27, 2018)

Turned out to be a masterpiece!


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## telemaq76 (Jul 5, 2018)

finally a clear night, i mean 4 clear hours, those nights are the shortest of the year ,and it was full moon, 
then best target was M13 i guess
120 subs 60 secondes, 25 darks, 15 flats, 200 offsets





with my canon 700da+500 4 is , neq6 pro


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## Click (Jul 5, 2018)

Very nice picture, telemaq76. Well done.


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## telemaq76 (Jul 5, 2018)

Click said:


> Stunning picture. Well done, basketballfreak6.


i would love to see one exposure, one single exposure,


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## basketballfreak6 (Jul 6, 2018)

telemaq76 said:


> Click said:
> 
> 
> > Stunning picture. Well done, basketballfreak6.
> ...



hey mate yea too easy here it is, SOOC jpeg:



Antares single sub pre-integration and stretchhing by Tony, on Flickr


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## telemaq76 (Jul 11, 2018)

thanks a lot, yeah you already have some signal on one sub, in my bad sky i m sure i will have nothing


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## jrista (Aug 31, 2018)

Wow! I'm amazed this thread is still going. Glad to see so many of you have gotten into astrophotography. (Heh, it's consumed me for the last few years...went all in on AP, so much so that I sort of wrapped my 600mm f/4 L lens in so much astro-related gear I couldn't really use it for anything else.) 

Some nice stuff here, though, guys.


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## Maximilian (Aug 31, 2018)

jrista said:


> Wow! I'm amazed this thread is still going. Glad to see so many of you have gotten into astrophotography. (Heh, it's consumed me for the last few years...went all in on AP, so much so that I sort of wrapped my 600mm f/4 L lens in so much astro-related gear I couldn't really use it for anything else.)
> 
> Some nice stuff here, though, guys.


Welcome back, John! 

It's been a long time since your last post.


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## jrista (Oct 26, 2018)

While I don't use Canon cameras anymore, as I switched to dedicated, cooled, mono astro cameras a while ago, here is something to get this thread going again:







HOO-styled blend






SHO-styled blend

"The Great Wall", part of "North America" nebula in Cygnus. A total of 24 hours of integration, acquired with an ASI183MM Pro camera, cooled to -15C, with AstroDon Ha, OIII and SII 3nm narrow band filters. Acquired with an Astro-Physics Mach 1 GTO mount and Sequence Generator Pro for automation.


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## Click (Oct 26, 2018)

Stunning pictures. Well done, Jon.


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## Don Haines (Oct 26, 2018)

jrista said:


> While I don't use Canon cameras anymore <snip>



The camera does not matter much, it’s the enthusiasm and the ability to plan/process the images that makes it great in this field... welcome back!


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## Valvebounce (Oct 27, 2018)

Hi Jon. 
As is usual from you, 2 very good shots. For the uninitiated amongst us (me) could you decifer the jargon please, I have no idea to what you refer with all the letters. Thanks. 

Cheers, Graham. 



jrista said:


> While I don't use Canon cameras anymore, as I switched to dedicated, cooled, mono astro cameras a while ago, here is something to get this thread going again:
> 
> HOO-styled blend
> 
> ...


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## jrista (Oct 29, 2018)

Valvebounce said:


> Hi Jon.
> As is usual from you, 2 very good shots. For the uninitiated amongst us (me) could you decifer the jargon please, I have no idea to what you refer with all the letters. Thanks.
> 
> Cheers, Graham.



Thanks, Graham!

For the acronyms, HOO stands for Hydrogen/Oxygen/Oxygen, or Ha/OIII/OIII. It is a particular kind of narrow band blend that gives a "natural" look from a color standpoint (hydrogen gas to reddish or pinkish, oxygen gas to a blue or cyan.) 

SHO stands for Sulfer/Hydrogen/Oxygen or SII/Ha/OIII. This is another kind of narrow band blend that is definitely "false color" in that hydrogen-alpha, which is definitely a red emission, is mapped to green. This is also sometimes called the Hubble Palette, as it is the standard blending palette often used for official hubble image reproductions. 

The underlying data here is the same...I've just blended the information in different ways to give it a different look.


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## Valvebounce (Oct 29, 2018)

Thanks Jon. 
I did try googling but the Ha came back as ‘hahnium (*Ha*)’ alternate name for Dubnium DB (105). 
Is your Ha H for hydrogen, a for alpha emissions or some other naming convention. 

Cheers, Graham. 



jrista said:


> Thanks, Graham!
> 
> For the acronyms, HOO stands for Hydrogen/Oxygen/Oxygen, or Ha/OIII/OIII. It is a particular kind of narrow band blend that gives a "natural" look from a color standpoint (hydrogen gas to reddish or pinkish, oxygen gas to a blue or cyan.)
> 
> ...


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## AlanF (Oct 29, 2018)

https://www.bbc.co.uk/news/in-pictures-45978380
Stunning photos from the winners of the Royal Observatory Greenwich's annual photography competition announced today.


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## Click (Oct 29, 2018)

Thanks for sharing, Alan. Amazing pictures.


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## jrista (Oct 29, 2018)

Valvebounce said:


> Thanks Jon.
> I did try googling but the Ha came back as ‘hahnium (*Ha*)’ alternate name for Dubnium DB (105).
> Is your Ha H for hydrogen, a for alpha emissions or some other naming convention.
> 
> Cheers, Graham.



Yes, Ha is hydrogen-alpha. I mentioned the full name in my post when I described how it was mapped to green in the SHO blend.

SII stands for Sulfur-II, and OIII stands for Oxygen-III, doubly ionized narrow band emissions from gaseous nebula.


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## Valvebounce (Oct 29, 2018)

Oops so you did, I missed that, sorry Jon.
Thanks for your patience.

Cheers, Graham.



jrista said:


> Yes, Ha is hydrogen-alpha. I mentioned the full name in my post when I described how it was mapped to green in the SHO blend.
> 
> SII stands for Sulfur-II, and OIII stands for Oxygen-III, doubly ionized narrow band emissions from gaseous nebula.


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## basketballfreak6 (Feb 14, 2019)

Have not had much luck where I am (Brisbane, Australia) with the weather but finally had clear skies few nights ago and finally had the chance to attempt Orion for the first time this season.

Taken from the backyard in Bortle 6 light pollution and crescent moon in the sky (for the most part)

Canon 760D modified + 100L Macro tracked with Sky-Watcher Star Adventurer



Orion Wide by Tony, on Flickr



Orion, Running Man, Horsehead and Flame by Tony, on Flickr


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## Don Haines (Feb 14, 2019)

basketballfreak6 said:


> Have not had much luck where I am (Brisbane, Australia) with the weather but finally had clear skies few nights ago and finally had the chance to attempt Orion for the first time this season.
> 
> Taken from the backyard in Bortle 6 light pollution and crescent moon in the sky (for the most part)
> 
> Canon 760D modified + 100L Macro tracked with Sky-Watcher Star Adventure



Nice!

I got an autoguider for my mount and have not had a clear night since November! It is shots like yours that keep me interested!


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## basketballfreak6 (Feb 14, 2019)

Don Haines said:


> Nice!
> 
> I got an autoguider for my mount and have not had a clear night since November! It is shots like yours that keep me interested!



Thanks Don! Hope weather clears up for you soon!

I've been doing everything unguided, actually a little frustrated at how finicky the Star Adventurer is with slightly heavier loads/longer focal lengths.

I know guiding will help but not sure if I should just bite the bullet and invest in a better mount.


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## Click (Feb 14, 2019)

Awesome. Greats shots, Tony.


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## Don Haines (Feb 14, 2019)

basketballfreak6 said:


> Thanks Don! Hope weather clears up for you soon!
> 
> I've been doing everything unguided, actually a little frustrated at how finicky the Star Adventurer is with slightly heavier loads/longer focal lengths.
> 
> I know guiding will help but not sure if I should just bite the bullet and invest in a better mount.


I live about a two hour drive from a bortle 1 zone, and intend to spend some time there this summer. Right now, I am still learning.


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## basketballfreak6 (Feb 14, 2019)

Click said:


> Awesome. Greats shots, Tony.


Thanks Click!



Don Haines said:


> I live about a two hour drive from a bortle 1 zone, and intend to spend some time there this summer. Right now, I am still learning.


That's awesome! That's about the same with me just been a bit lazy driving out so been doing it in the backyard lol


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## rpt (Apr 8, 2019)

So this is my first try of the milky way core. Took it on the 10th of last month. 4 shots merged with Sequator. I obviously need to shoot again but thought that I would share.

Shot with my 5D3 and 24-105 @28mm at F/4
Shot 1: ISO 3200 20 sec
Shot 2: ISO 3200 13 sec
Shot 3: ISO 6400 13 sec
Shot 4: ISO 12800 13

Venus at bottom right. Jupiter top middle-ish. Saturn halfway between the two in the line segment.

Please comment. 


sec


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## karishmab (Apr 22, 2019)

rpt said:


> So this is my first try of the milky way core. Took it on the 10th of last month. 4 shots merged with Sequator. I obviously need to shoot again but thought that I would share.
> 
> 
> View attachment 183813



You have captured this photo so amazingly! I really appreciate your work! For me, it is added in my favorites!


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## rpt (Apr 23, 2019)

karishmab said:


> You have captured this photo so amazingly! I really appreciate your work! For me, it is added in my favorites!


Thanks. It is quite average. Hope to get a better shot in the next few months...


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## Don Haines (Apr 23, 2019)

basketballfreak6 said:


> Thanks Don! Hope weather clears up for you soon!
> 
> I've been doing everything unguided, actually a little frustrated at how finicky the Star Adventurer is with slightly heavier loads/longer focal lengths.
> 
> I know guiding will help but not sure if I should just bite the bullet and invest in a better mount.


I made a brass counterweight for mine, and the hole is off-centre so I can help balance the camera better.


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## FramerMCB (Apr 23, 2019)

Mt Spokane Photography said:


> Living up in the Northwest, our availability of clear weather is limited to the summer, and then we have a lot of light contamination from Spokane, starting about 10 miles South of us. We are in the country, as far as the neighborhood, but not away from the city light.
> 
> I've been up in Northern British Columbia, 100 miles from anything but tiny villages, and its truly amazing what you can see on a clear night. Astrophotography would be a great hobby up there.


Eastern Oregon is also a great area for dark-night sky viewing/pictures. Especially the south-eastern corner of the state - south and east of Malheur Wildlife Refuge for example - think Owyhee river and/or Steens Mountain...


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## basketballfreak6 (Apr 25, 2019)

Don Haines said:


> I made a brass counterweight for mine, and the hole is off-centre so I can help balance the camera better.



I've invested in a (relatively) cheap guiding setup since we last spoke. Haven't had much chance with it due to crappy weather we've been getting but with what little time I've had to muck around with it so far I seem to get pretty good results with 2 min subs on ~500mm FOV (crop body + 200mm + 1.4x TC) on the Star Adventurer.


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## basketballfreak6 (May 8, 2019)

Antares region shot from Brisbane suburban backyard (Bortle 5 sky)



Antares Region by Tony, on Flickr


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## Click (May 8, 2019)

Stunning picture. Well done, Tony.


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## basketballfreak6 (May 9, 2019)

Click said:


> Stunning picture. Well done, Tony.



Thanks Click!


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## basketballfreak6 (Jun 4, 2019)

Lagoon + Trifid



Lagoon + Trifid by Tony, on Flickr

Only 40 minutes of total integration time in Bortle 5 sky, threw away 2/3 of subs because it was windy AF here last night


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## Click (Jun 4, 2019)

Beautiful shot, Tony.


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## basketballfreak6 (Jun 9, 2019)

Click said:


> Beautiful shot, Tony.


Thanks Click!


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## basketballfreak6 (Jul 24, 2019)

Antares and Blue Horsehead Nebula by Tony, on Flickr

Also found out last night that my 70-200L II zoom creeps a bit which I thought was interesting considering it's internal zoom?


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## Click (Jul 24, 2019)

Awesome. Stunning picture. Well done, Tony.


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## basketballfreak6 (Jul 24, 2019)

Click said:


> Awesome. Stunning picture. Well done, Tony.



Thank you Click!


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## basketballfreak6 (Aug 25, 2019)

Milky Way, Antares and Rho Ophiuchi by Tony, on Flickr


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## Click (Aug 25, 2019)

Another stunning picture. Well done, Tony.


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## basketballfreak6 (Aug 25, 2019)

Click said:


> Another stunning picture. Well done, Tony.



Cheers mate


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## basketballfreak6 (Feb 19, 2020)

First imaging session in like over 4 months (with the bushfires and now rain/storm in Australia the last few months clear nights are hard to come by); had a brief few hours of clear skies the last couple of nights.

Roughly 3 hours total imaging time short in suburban Bortle 5 sky:



Orion and Running Man Nebula by Tony, on Flickr


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## Joules (Feb 19, 2020)

basketballfreak6 said:


> Roughly 3 hours total imaging time short in suburban Bortle 5 sky:


Amazing! As always.

I have a little bit of data on Orion that I wanted to expand on several occasions, but the clouds kept me from trying. Hopefully that changes at some point and I'll get even remotely close to your results. How much time roughly goes into editing with your work flow, if you don't mind me asking?


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## basketballfreak6 (Feb 19, 2020)

Joules said:


> Amazing! As always.
> 
> I have a little bit of data on Orion that I wanted to expand on several occasions, but the clouds kept me from trying. Hopefully that changes at some point and I'll get even remotely close to your results. How much time roughly goes into editing with your work flow, if you don't mind me asking?



Thanks mate! Yea weather can be a pain.

Umm hard for me to say but data integration would've taken me over 1 hour easily especially since I did a stack for the main body and the bright core. Then I load them up in Lightroom to touch up before bringing into Photoshop to blend in the core and try to correct the colour difference between the 2 stacks and do star size reduction before finishing it off again Lightroom. So easily quite a few hours as there is a bit of trial and error element involved too. I am more amateurish at this so I might not be the best person to ask haha.


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## Don Haines (Feb 19, 2020)

basketballfreak6 said:


> First imaging session in like over 4 months (with the bushfires and now rain/storm in Australia the last few months clear nights are hard to come by); had a brief few hours of clear skies the last couple of nights.
> 
> Roughly 3 hours total imaging time short in suburban Bortle 5 sky:
> 
> by Tony, on Flickr



Well done!


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## Click (Feb 19, 2020)

Stunning. Great shot. Well done,Tony.


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## basketballfreak6 (Feb 20, 2020)

Don Haines said:


> Well done!





Click said:


> Stunning. Great shot. Well done,Tony.



Thanks guys!


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## basketballfreak6 (Mar 29, 2020)

Roughly 4 hours total data over 3 nights in Bortle 5 light pollution:



Horsehead and Flame nebulae by Tony, on Flickr


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## Click (Mar 29, 2020)

WOW! Great shot. Beautiful colours.


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## basketballfreak6 (Apr 4, 2020)

Click said:


> WOW! Great shot. Beautiful colours.


Thanks Click!


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## basketballfreak6 (May 26, 2020)

2 hours on Trifid Nebula with Canon 77D and Sigma 150-600C

https://flic.kr/p/2j5K4Rc]

Trifid Nebula[/url] by https://www.flickr.com/photos/basketballfreak6/]Tony[/url], on Flickr


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## Click (May 26, 2020)

Stunning picture. Well done, Tony.


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## basketballfreak6 (May 27, 2020)

Click said:


> Stunning picture. Well done, Tony.


Thanks Click!


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## Maximilian (May 28, 2020)

basketballfreak6 said:


> by Tony, on Flickr


Hey, Tony! 
Fantastic colors and rendering of details that you offer here with your pics of far off worlds. 
Congrats to your work.

Can you give me a short insight to your processing here or via PM? 
Thanks in advance.


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## basketballfreak6 (Jul 19, 2020)

Would love to be chasing Neowise but can't see it from where I am so here's Antares and Rho Ophiuchi instead:



Antares and Rho Ophiuchi by Tony, on Flickr


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## Click (Jul 19, 2020)

Awesome. Beautiful colours. Great shot, Sir!


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## HenryL (Jul 19, 2020)

Gorgeous photo!


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## basketballfreak6 (Jul 19, 2020)

Click said:


> Awesome. Beautiful colours. Great shot, Sir!





HenryL said:


> Gorgeous photo!


Cheers guys!


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## basketballfreak6 (Aug 9, 2021)

Was locked down here in Brisbane, Australia over the weekend so got around to doing some driveway astro which I've not done in ages. Shot with a modified Canon 77D with 100mm L Macro tracked with an AZ-GTi. Pretty happy with what I got with just 3 hours of data under Bortle 5/6 sky:



Antares/Rho Ophiuchi and Blue Horsehead by Tony, on Flickr


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## Click (Aug 9, 2021)

Great picture! Well done, Tony.


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## basketballfreak6 (Aug 9, 2021)

Click said:


> Great picture! Well done, Tony.


Thanks Click!


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## basketballfreak6 (Mar 9, 2022)

Been real lazy and inactive and not posted in ages...taken last night under Bortle 5 sky and waxing crescent moon. First clear night in ages here is Brisbane, Australia; weather's been terrible some of you's may have seen the news we just suffered through the worst flood we've had in like a decade.



Horsehead and Flame Nebula by Tony, on Flickr


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## Click (Mar 9, 2022)

Beautiful shot. I really like your picture, Tony. Well done.


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## gruhl28 (Mar 9, 2022)

Gorgeous shot, Tony. Can you post some of the details of what camera and lens/scope you used, exposure, etc.?


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## basketballfreak6 (Mar 9, 2022)

Click said:


> Beautiful shot. I really like your picture, Tony. Well done.





gruhl28 said:


> Gorgeous shot, Tony. Can you post some of the details of what camera and lens/scope you used, exposure, etc.?


Thanks guys!

Gear: modified Canon 77D and Sigma 150-600mm Contemporary at 400mm and tracked and controlled with a Skywatcher AZ-GTi + ZWO ASIAIR + 30F4 guidescope + ASI120MM Mini combo.

Image details: 84x 2 minute subs at f/6.3 and ISO 400 + 20x darks, flats and dark flats.

Picture came out nice but really could use more data especially shot under light pollution.


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