# Lens dilemma for night sky



## flajcsi (Nov 19, 2013)

Hi.

I'm looking forward to buy some new lenses. The primary goal would be landscapes and night sky photos.
I'd like to mention that I own a Canon 5d Mark III so noise is acceptable, but I wanna lower that.
I'm looking right now to:
Canon 16-35 f2.8 II L
Canon 16-35 f2.8 II L + Rokinon 24 F1.4
Canon 17-40 f4 L + Rokinon 24 F1.4 
Canon 17-40 f4 L + Canon 24 F1.4 L

Keeping in mind that I need option for filters too and aperture for night sky(no star trail). Sky trackers are not an option because of the foreground.
I read a lot about the Canon 24 vs Rokinon 24 coma problem. 
In the future I also wanna buy a Canon 24 TS-E lens, but that's gonna wait.

I'm curios about your opinions. Renting these lenses, unfortunately is not an option.
Thank you for your time and patience.


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## gigabellone (Nov 19, 2013)

Have you considered the Samyang/Rokinon 14/2.8? It looks like it's very sharp and woth very low chromatic aberrations and no coma. I'm considering it myself as my night sky lens. I think that the 17-40/4 might be a little too slow to photograph stars.


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## cellomaster27 (Nov 19, 2013)

Well, for both landscapes and night shots of stars, I like things real wide. But you want a large aperture for night stars, to get them without the trails.. Meaning medium-ish shutter speed. But you want small apertures for landscape, considering it's during the day. The canon 24 1.4 would be my pick.. Due to the max aperture. What about the canon 14mm 2.8 L? Since 5m3 has excellent ISO capabilities.


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## NWPhil (Nov 19, 2013)

Not sure if the new canon 24-70 2.8 mk2 has a lesser "comma" issue....but I would assume not, and would go instead with the Rokinon 14mm - as suggested already, along with the Zeiss 21mm. There are a few options with older Contax and Leica zoom lenses whithin the 24-80mm range , allowing a bit more flexibility and still affordable - you should do a search in some other nightscape forums.
No need for AF in nightscapes, and the hard stop at infinity is really usefull, along with live view - sure, low noise iso helps a lot too.

In sum:
Rokinon 14mm for sure
- assuming that your budget it's around +/- 2k, then you will have to compromise between night and day, zoom or prime combination for a second lens


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## Twostones (Nov 20, 2013)

I have had good luck shooting the night sky with the Canon 28mm f1.8 lens. I shoot with it stopped down to 2.0 and there about. I do the same with the 50mm 1.4. I have the Canon 17- 40mm F4.0 but it takes longer exposures than I like. I like to shoot at 400 to 800 ISO. I have shot as high as 1600 ISO with acceptable results.


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## Mr Bean (Nov 20, 2013)

flajcsi said:


> Canon 16-35 f2.8 II L
> Canon 16-35 f2.8 II L + Rokinon 24 F1.4
> Canon 17-40 f4 L + Rokinon 24 F1.4
> Canon 17-40 f4 L + Canon 24 F1.4 L


I'd look at a zoom + Zeiss 21mm. The problem with night sky shooting is that you need speed and the lenses mentioned (the f1.4's) suffer badly from a bunch of optical aberrations, with coma being the worst (the Canon is a shocker). At f2.8 on a 5D3, the ISO capabilities are sufficient to cope with a stop or two loss. The Zeiss 21mm is crazily sharp wide open, but I went for the Zeiss 15mm because I wanted a wider lens.

You could go for the Canon 17-40 for landscape and Zeiss 21mm for night shooting, but it does a great job for landscapes at f8


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## JPAZ (Nov 20, 2013)

gigabellone said:


> Have you considered the Samyang/Rokinon 14/2.8? It looks like it's very sharp and woth very low chromatic aberrations and no coma. I'm considering it myself as my night sky lens. I think that the 17-40/4 might be a little too slow to photograph stars.



+1


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## yorgasor (Nov 20, 2013)

The problem with the Rokinon 14/2.8 is that it will not let you add a filter, although you just might be able to find some kind of wonky adapter. But even in spite of that, I still recommend the Canon 17-40mm + Rokinon 14mm. For scenes where you do need a filter, you can use the Canon 17-40mm. The Rokinon would do very well at night for stars, but will still do wonders in the day when you don't specifically need a filter. I think you'll get the best of both worlds with that combination.


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## amoore00357 (Nov 20, 2013)

How about the Tokina 16-28 2.8? 

From what I herd is that the Tokina is close to the 16-35 in quality and its alot cheaper ($700) compared to around $1,600. 

Then if you need 14mm you can get the canon or rokinon.


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## Andy_Hodapp (Nov 20, 2013)

I shoot with a mkii, I've had alright luck with the 50mm 1.8 when used to create panoramas. I've also used the 17-40 and would not recommend. I'm on the same boat as you and I'm choosing between selling my 17-40 and getting a Tokina 16-28, though the lack of filters bothers me, especially sense my 17-40 would be in the trash right now had it not been for one. The rokinon 14, 24 and 35 all sound like great lenses and I'm trying to make the choice between them. 

Pano with the 50







Shot with the 17-40


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## Ruined (Nov 20, 2013)

I haven't tried it myself, but I heard the Canon f/1.4L II is good for star shooting once stopped down to f/2.8, as coma issues subside at that point.


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## gigabellone (Nov 20, 2013)

Ruined said:


> I haven't tried it myself, but I heard the Canon f/1.4L II is good for star shooting once stopped down to f/2.8, as coma issues subside at that point.



If you have to stop down to f/2.8 you might as well save a grand and buy the 24/2.8 IS, which is quite good straight from maximum aperture. Unless, of course, you need f/1.4 for other works.


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## nubu (Nov 20, 2013)

If you want to have good star images in the corners you will have to stop down most (all wider) of the lenses for one to two stops, sometimes even 3. So the argument to save money when using at 2.8 optic instead of a 1.4 stopped down to 2.8 is not correct since the 2.8 optic needs to be stopped down again to at least 4.... I even stop down fantastic lenses like the 135/2, the 200/2.8 or the 300/2.8 and 500/4 since you benefit a lot in quality when doing this in astrophotography!.


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## Mr Bean (Nov 20, 2013)

The other benefit of the Zeiss 21mm, other than being tack sharp wide open at f2.8 is that it has a hard infinity stop. Sooooo much easier to set in the dark than fiddling with Live View to get focus on an AF lens.


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## gigabellone (Nov 20, 2013)

nubu said:


> If you want to have good star images in the corners you will have to stop down most (all wider) of the lenses for one to two stops, sometimes even 3. So the argument to save money when using at 2.8 optic instead of a 1.4 stopped down to 2.8 is not correct since the 2.8 optic needs to be stopped down again to at least 4.... I even stop down fantastic lenses like the 135/2, the 200/2.8 or the 300/2.8 and 500/4 since you benefit a lot in quality when doing this in astrophotography!.


Maybe you're right, i never used these lenses and i can't swear by it, but if we can trust DxOMark, it looks like the two lenses behave close enough to make a 1000$/€ price difference look a bit of an exaggeration. Check the images attached to this post, i'm looking for a wideangle too, and i need some feedback. 


Mr Bean said:


> The other benefit of the Zeiss 21mm, other than being tack sharp wide open at f2.8 is that it has a hard infinity stop. Sooooo much easier to set in the dark than fiddling with Live View to get focus on an AF lens.


I agree with you, the Zeiss 21/2.8 is the best at astrophotography, but MF makes it a very specialized lens.


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## flajcsi (Nov 20, 2013)

Thank you for all the responses.
My big concern is that I read about the 24mm f1.4L coma and some review said that the Rokinon does a better job with this problem. It's kinda unbelievable, that a 1800 dollar lens is being beaten by a 600 dollar one. Again I'm looking at the widest aperture possible, because of the noise.
The Zeiss lenses would be a good idea, but those are 2.8.
Autofocus is not an issue. My priority is light and image quality.
I tried my 50mm 1.4 for this kind of photography, but it's not wide enought.
Something between 14-24.
Thanks again for the help and I'm curious for all of your experience with these lenses.


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## nubu (Nov 20, 2013)

Stars are the hardest test for chromatic abberations, coma and astigmatism. Moreover, in more light polluted areas vignetting is quite obvious. Whereas I will not question the high quality of the Zeiss optics (had many of them in my analog Contax time) wide open is not an option if you want high quality results. This link is somewhat outdated but still valid for its basic message: http://www.astropix.com/HTML/I_ASTROP/LENSES.HTM


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## nubu (Nov 20, 2013)

flajcsi said:


> ... Again I'm looking at the widest aperture possible, because of the noise. ...



Astrophotographers beat noise by exposure time (stacking of many indv. exposures) and not open aperture!
It is much easier and cheaper to double exposure times than to double apertures! Only in special cases (astrophotography incl. landscape or moving phenomena like aurora) one fully opens up to have the shortest exposure times possible.... I fully agree that manual focus is perfectly o.k. since compared to any meaningful exposure time the manual focusing time with e.g. live view in 10x mode is negligible. In the analog times it was much harder with test images or knife edge focusing....


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## nubu (Nov 20, 2013)

Sorry I forgot to make a note on Sky trackers which you excluded. This is only partly true even for pics including landscape!

Modern systems have so called half speed modes correcting only have of earths rotation and by this also causing smearing problems in the landscape part later. So by this it is possible to gain some extra photons on both the landscape and the starry sky ... Examples are: http://www.vixenoptics.com/mounts/polarie.html or the by me preferred: http://www.ioptron.com/index.cfm?select=productdetails&phid=cffad01a-797c-4cf4-beb8-a64bc8e09b06 (its the more complete package for a better price)


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## noisejammer (Nov 20, 2013)

I did quite a few tests using my Zeiss ZE 25/2, 50/2 MP and 100/2 MP. These are all superb lenses but like all lenses, they exhibit a combination of vignetting, optical aberration and field curvature.

On an APS-C frame, they can all be used stopped down 1 stop. On a full frame, they they are not good enough for astrophotography unless stopped down to f/5.6, f/4 and f/4 respectively. The same conclusion largely holds for the 21/2.8 except that the field of view becomes something of a liability rather than a help.

This should hardly be a surprise - even the very fastest astrograph from Takahashi operates at f/2.8 which is really about T/3.5 and can only illuminate an APS-C frame. 

You can draw your own conclusions on how this relates to the 16-35 and 17-40, neither of which is particularly sharp unless stopped down considerably. I have no experience of the 14 mm Samyang but I friend uses the 14 mm Canon lens quite successfully.

Secondly, I honestly don't know what the OP's problem is with a sky tracker. You can get a sharp foreground and sharp stars by layering two images. As others have pointed out, it is sensible to stack the astro-image so that you can suppress noise. It may have been linked to above but this ebook is worth study http://astropix.com/BGDA/BGDA.HTM .

If cost is the issue, a sky tracker is easy to make - basically two pieces of wood and a hinge and a screw to rotate at 1 rpm using your finger. Look up "barn door tracker." Here's a very basic one that's good for 30 minutes at least... http://psychohistorian.org/display_article.php?id=201303261529_barn-door


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## mackguyver (Nov 20, 2013)

I was just looking into this very thing yesterday and it looks like the 24-70 f/2.8 II has the lowest coma of just about any Canon lens (other than the super teles):
http://www.lenstip.com/358.7-Lens_review-Canon_EF_24-70_mm_f_2.8L_II_USM_Coma__astigmatism_and_bokeh.html

Lenstip is about the only site that specifically tests for it. Sadly my beloved 24 f/1.4 II doesn't perform so well:
http://www.lenstip.com/245.7-Lens_review-Canon_EF_24_mm_f_1.4L_II_USM_Coma_and_astigmatism.html

For wider angles, the others are right, the Samyang 14 mm f/2.8 ED AS IF UMC is your best bet and blows away the 14 f/2.8 II:
http://www.lenstip.com/239.7-Lens_review-Samyang_14_mm_f_2.8_ED_AS_IF_UMC_Coma_and_astigmatism.html

Check out their other reviews too if you want to to find the right lens to make sure your stars are still round in the corners


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## extremeinstability (Nov 20, 2013)

This isn't done yet, but I recently rented the Canon 14, 24, 16-35 and 17-40 along with my Samyang 14 and 24 and Zeiss 21 to test exactly this stuff. http://www.extremeinstability.com/lenses.html Guessing you can get the idea from that right now. The Samyang 14 and 24 can both be used wide open on stars no problem. Canon's are a joke on stars. And otherwise still aren't worth the money. Unless one doesn't care for corners I guess.


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## mackguyver (Nov 20, 2013)

extremeinstability said:


> This isn't done yet, but I recently rented the Canon 14, 24, 16-35 and 17-40 along with my Samyang 14 and 24 and Zeiss 21 to test exactly this stuff. http://www.extremeinstability.com/lenses.html Guessing you can get the idea from that right now. The Samyang 14 and 24 can both be used wide open on stars no problem. Canon's are a joke on stars. And otherwise still aren't worth the money. Unless one doesn't care for corners I guess.


extremeinstability, when I said Lenstip was about the only place I had seen coma tests, your site was the other site, but I didn't have your URL. Thanks for posting and keep up the great tests!


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## extremeinstability (Nov 20, 2013)

I will be adding full size image examples for download once I get that far. But at least on the 16-35 and 17-40 these two should give one an idea. Only 6 seconds long so no moving stars like the edges look. 

http://www.extremeinstability.com/lenstestimages/blurring-canon1635.jpg
http://www.extremeinstability.com/lenstestimages/blurring-canon1740.jpg


That should give a person a general idea of the sharpness fall off on either of those lenses wide open at the wide ends. 17-40 seems it holds onto sharpness further out then falls the hell off hard. Sure one is F4 and the other F2.8. But clearly it pays to go prime when it comes to corners and stay away from Canon when it comes to coma.


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## extremeinstability (Nov 20, 2013)

mackguyver said:


> extremeinstability said:
> 
> 
> > This isn't done yet, but I recently rented the Canon 14, 24, 16-35 and 17-40 along with my Samyang 14 and 24 and Zeiss 21 to test exactly this stuff. http://www.extremeinstability.com/lenses.html Guessing you can get the idea from that right now. The Samyang 14 and 24 can both be used wide open on stars no problem. Canon's are a joke on stars. And otherwise still aren't worth the money. Unless one doesn't care for corners I guess.
> ...



Yeah lens tip was the only place I've seen it too. I never paid much attention to it till I bought a Canon 24L II and tried to shoot the night sky with it. Heck didn't even know about it till then. Using that I was like, holy crap what the hell, the outer third at least of the sky is ruined lol. Then found lens tip and well swapped that Canon for the Zeiss 21. Eventually wound up with the Samyang 14 and 24s which are quite scary good. I now need to get the 24 centered if that is the issue because its good side is just straight up ridiculous at F1.4 even. And the bad side is still as good as the Canon 24L II wide open lol. It just matters where the focus is set at infinity. I need to get it back out at night and make sure I set it so it is splitting the difference. Then compare to the Canon again. But it has to be better. It's worlds better with coma.


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## wearle (Nov 21, 2013)

I've tried many of the prime lenses, and the best I have found is the Zeiss Distagon 15mm f/2.8. It is very expensive at $3000. I can only afford to rent it, but the micro-contrast and color is just amazing. It's hard to explain how good the RAW images look with this lens. I've never seen anything like it. Yes, the Samyang is significantly cheaper, but I would be willing to bet it doesn't even come close to the "look" of the Zeiss glass. 

For meteor photography, I stop the Canon 14mm f/2.8L down to f/4.0. There is still a lot of aberrations in the corners. I've come to accept that fact.  I stop the Canon 24mm f/1.4L down to f/2.8 with just minor aberrations in the corners. I sure hope Canon's updates improve their coma problem; however, I would be surprised if they do. I'm looking forward to seeing what Zeiss puts out in their Otus line. I'd be willing to spend $4000 on a lens that has excellent stars stopped down to f/2.0 or so, especially if it is 21mm or 24mm focal length. That would be a dream.  I have included a few non-cropped examples.

You can always rent the Zeiss lens. The only downside to renting the Zeiss lens is you'll want to buy one afterwards. 

Wade


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## sanj (Nov 21, 2013)

Well done Wade!
Would you be kind enough to share technical details?


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## optikus (Nov 21, 2013)

Hello,

for optimal results in night-sky applikation with relatively low cost I propose

Y/C-Zeiss Distagon for the low end if focal length, adaption to EOS is no serieous problem, but not all lenses fit with full format mirror (!) - and modding the mirror is not anyone's business - but if more often used no bad idea - concerning the costs of newer ultra-wide lenses and regarfing the outstanding quality of the Zeiss-lenses.

For 50 -> 350mm focal length you have the option of using the Hasselblad-F-Lenses, perfect flat and very very sharp, nearly no vignetting due to the large image-circle. Adapters in very good brass quality are on the market.

My five pence,

Joerg


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## wearle (Nov 22, 2013)

sanj,

Thanks! 

Here are the details:

Photo 1
Zeiss Distagon 15mm f/2.8
Stopped down to f/3.5
Canon 5D3
ISO 4000
60 seconds 
unguided equatorial mount

Photo 2
Canon EF 8-15mm f/4.0L
Wide-open at f/4.0
Canon 1D-X
ISO 6400
40 seconds 
fixed tripod

Photo 3
Canon EF 14mm f/2.8L
Stopped down to f/4.0
Canon 5D2
ISO 3200
60 seconds 
unguided equatorial mount

Photo 4
Canon EF 24mm f/1.4L
Stopped down to f/2.8
Canon 5D3
ISO 2000
62 seconds 
unguided equatorial mount

Wade


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## gigabellone (Nov 25, 2013)

I don't know if this is going to be of any help, but my choice for this kind of pictures will be the Samyang 14/2.8. According to this review, it is a decent performer, and the price is very low compared to UWA from other manufacturers.


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## CreationHeart (Nov 26, 2013)

I recommend a used canon 15mm f2.8 fisheye


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## dswtan (Nov 27, 2013)

wearle said:


> I'd be willing to spend $4000 on a lens that has excellent stars stopped down to f/2.0 or so, especially if it is 21mm or 24mm focal length. That would be a dream.


Wade - have you tried the Samyang/Rokinon/Bower options? For a tenth of the cost, you can live the dream today! 8)

I took the same path as extremeinstability and naively wasted shots on the 24L II. I'm sure Zeiss is nice, but why bother when the Korean lenses are so well-suited to astrophotography. This is one of those rare cases of a true bargain! 

BTW, this has a good summary of the coma issue, just to add to the resources already in this thread: http://forums.dpreview.com/forums/post/50949062


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## Ruined (Nov 27, 2013)

I have read on astronomy blogs that the 24L II is actually quite good when stopped down to f/2.8 with minimal coma at edges. If you are trying to shoot it wide open at f/1.4 that is why you had a problem.


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## wearle (Nov 27, 2013)

dswtan said:


> Wade - have you tried the Samyang/Rokinon/Bower options? For a tenth of the cost, you can live the dream today! 8)



I haven't tried them yet. I plan on renting the 14mm and 24mm in the future to see how they compare to the Zeiss. Although the Zeiss 15mm is very expensive, the micro-contrast and look are second to none.  If I were rich, I would go with the Zeiss 15mm, but since I'm not, I'll likely get the Samyang/Rokinon/Bower lens.

Wade


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## TBiRD (Nov 27, 2013)

dswtan said:


> wearle said:
> 
> 
> > I'd be willing to spend $4000 on a lens that has excellent stars stopped down to f/2.0 or so, especially if it is 21mm or 24mm focal length. That would be a dream.
> ...



Yep I got the Samyang 14mm 2.8 and really love it. Got the correction profile for lightroom too.


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## JustMeOregon (Nov 27, 2013)

TBiRD said:


> dswtan said:
> 
> 
> > wearle said:
> ...



@ TBIRD I've been thinking about the Samyang 14 for a while, but haven't pulled the trigger because of a lack of a Lightroom lens correction profile... Where did you get your LR correction profile for the Samy-14? Is it Mac or PC (does it matter)?


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## wearle (Jan 2, 2014)

To all,

I just rented and star tested the Rokinon 14mm T/3.1. I'm very impressed. It can be used wide-open on FF with little, if any, aberrations in the corners. It is a little bit difficult to focus; otherwise, it is a stellar performer in the world of astrophotography. I immediately purchased it from LensRentals.com. This way I know I have an excellent copy since I already tested it. 

Although the Zeiss 15mm shows better micro-contrast, it is not as well corrected and for 8X the cost, probably not worth it if only used for taking nighttime photos.

Wade


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## scyrene (Jan 2, 2014)

A few things.

First, if you're not viewing at full size or anything close, problems with coma, chromatic aberration, and astigmatism are less important. Resized to average web viewing can cover a lot of sins.

Second, as Nubu said, you can use tracking mounts with reduced speed if you're shooting foreground/horizon too. I've never used the 1/2x speed on my iOptron SkyTracker, but others have with good results (within reason of course, especially at reduced size).

Third, the Samyang/Rokinon f/2.8 is a wonderful lens for daytime and night ultra wide angle work. You can't get front-mounted filters for it, but I was wondering what kind you meant? If astro filters, the slot-in type (for crop sensor) are good (this is why I use it on the 50D). Other wide angle lenses may take rear-mounted gel filters.

One thing not widely discussed is ability to focus. I would use the 24-105 f/4 for astro work, but it is too dark and the magnification too low (even at Live View x10) to get accurate focus on stars at 24mm, so has never worked for me. You can try different manual focus points through trial and error - I found the Samyang's less loose focus ring easier for this. But with a wider aperture lens, the brighter image can help with focus.

Stopping down isn't always worth the effort. I have experimented with the 85 f/1.2 II at various apertures, and I'm not sure the benefits of less vignetting and distortion at narrower apertures exceeds the loss of light. Do look into flat frames, which are master images taken that can be used to cancel out most of the colour and vignetting problems (but not coma etc; NB it can be hard getting flat frames at the shortest focal lengths).

One last thing. It may be cheaper and easier, depending on where you live, and if you drive, to go to darker locations. Most of what I do in astro work is fighting light pollution. If you can go somewhere dark, any camera will take good wide angle astro images. Good luck in any case!

Below: Milky Way from suburbia, Samyang 14mm (70mins stacked + tracked, no darks/flats).


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