# More Astrophotography With the Sigma 14mm f/1.8 DG HSM Art Lens



## Canon Rumors Guy (Jul 18, 2017)

```
DPReview has posted an even more in-depth look at how the Sigma 14mm f/1.8 DG HSM Art series lens works for astrophotography.</p>
<p><strong>From DPReview:</strong></p>
<blockquote><p>As I mentioned, my go-to lens for wide-field astrophotography is the Nikkor 14-24mm F2.8G ED. If I needed to pick just one lens to photograph the night sky, would I trade it for the Sigma 14mm F1.8 DG HSM Art? The answer is yes. Although I often use the Nikkor lens at different focal lengths to photograph buildings and monuments (it’s the perfect lens for cathedral interiors), I rarely use it to photograph the sky at focal lengths others than 14mm. When taking single shots of the night sky (something I often do while other cameras are shooting time-lapse sequences) the extra 1.3 f-stop would allow me to take shorter exposures and use that gained time to creatively experiment with different compositions and angles. <a href="https://www.dpreview.com/articles/1717621214/astrophotography-with-the-sigma-14mm-f1-8-art-lens">Read the full story</a></p></blockquote>
<p>It looks like if you’re into shooting the night skies, this new Sigma is going to leave you very impressed.</p>
<p><strong>Sigma 14mm f/1.8 DG HSM Art:</strong> <strong><a href="https://bhpho.to/2rkYCub">B&H Photo</a></strong> | <strong><a href="https://mpex.com/sigma-14mm-f1-8-dg-hsm-art-lens-canon.html?acc=3">MPEX</a></strong> | <a href="http://www.awin1.com/cread.php?awinaffid=292297&awinmid=6241&p=https%3A%2F%2Fwww.parkcameras.com%2Fp%2FG242324C%2Fcanon-lenses-ef-mount%2Fsigma%2F14mm-f18-dg-hsm-art-ultra-wide-angle-canon-fit-lens">Park Cameras</a> (UK)</p>
<span id="pty_trigger"></span>
<div style="font-size:0px;height:0px;line-height:0px;margin:0;padding:0;clear:both"></div>
```


----------



## BeenThere (Jul 18, 2017)

The time lapse sequences were pretty interesting. For those of you who shoot time lapses, what time interval would you estimate was used between frames? I think there is something wrong with the frame exposure time marked on the final sequence (star trails). Trails that long would not occur in 13 seconds.


----------



## testthewest (Jul 18, 2017)

BeenThere said:


> The time lapse sequences were pretty interesting. For those of you who shoot time lapses, what time interval would you estimate was used between frames? I think there is something wrong with the frame exposure time marked on the final sequence (star trails). Trails that long would not occur in 13 seconds.



Yes, I was wondering as well: Why does he get star trails with 13sec, but not with the previous pictures with 15 sec.

For someone who wants to try this with the new 6D II when it finally is in my hands: what shutter speed is optimal for these nighttime time lapse videos of the sky?


----------



## nemtom (Jul 18, 2017)

testthewest said:


> BeenThere said:
> 
> 
> > The time lapse sequences were pretty interesting. For those of you who shoot time lapses, what time interval would you estimate was used between frames? I think there is something wrong with the frame exposure time marked on the final sequence (star trails). Trails that long would not occur in 13 seconds.
> ...



The 13sec sample is a made by using a low pass filter (meaning that each video frame is a windowed average of multiple exposures). It is clearly visible at the beginning of the scene, where the trails are growing.

To figure out how much is the pause between the exposures, one can use the same take, and check that dashed line caused by an airplane. Obviously each dash is one exposure, and the break in between is the time between exposures. As one exposure is 13sec, one can simply multiply that with the ratio of those lengths. As a rule of thumb no time interval should occur between exposures - at least as minimal as possible, and should happen as rarely as possible, so each exposure should take as long as possible with the camera. Whenever I'm shooting on small format, I aim to 5-10 minutes long exposures, and no interval between them.

The time needed to avoid trails depends on the resolution of the sensor, the focal length (see '500 rule') and the direction you're looking at. The easiest is to find your preferred exposure time yourself. Just shoot a couple of images between 10 and 30 sec at your intended direction the night before with the same lens, and find the longest without trails. Don't forget to examine the images pixel level, on a computer. For 6DII I think it will be around 20-25sec for a 14mm lens.


----------



## Tangent (Jul 18, 2017)

You need to get to 2.8 to eliminate the invading saucer fleet in the corners -- and my $250 Rokinon 14 2.8 is already sharp and coma-free at 2.8. Lighter in weight, too. Over a thousand dollars cheaper. Though it's quite nice, I do not see this new Sigma lens as a compelling value proposition for astrophotography work. I believe I'm going to be able to avoid a GAS attack on this one!


----------



## Busted Knuckles (Jul 19, 2017)

Tangent said:


> You need to get to 2.8 to eliminate the invading saucer fleet in the corners -- and my $250 Rokinon 14 2.8 is already sharp and coma-free at 2.8. Lighter in weight, too. Over a thousand dollars cheaper. Though it's quite nice, I do not see this new Sigma lens as a compelling value proposition for astrophotography work. I believe I'm going to be able to avoid a GAS attack on this one!



2.8 on the 1.8? or are you saying all lenses coma wider than 2.8?


----------



## SecureGSM (Jul 19, 2017)

You have overlooked that the Sigma is virtually vignetting free at F2.8 and extremely low distortions and CA. That will definitely benefit IQ in outer areas of the frame. It is not as simple as one would thought. And no, you cannot compensate for the vignetting in post without IQ sacrifice due to increased noise levels. 
This lens is on my shopping list.



Tangent said:


> You need to get to 2.8 to eliminate the invading saucer fleet in the corners -- and my $250 Rokinon 14 2.8 is already sharp and coma-free at 2.8. Lighter in weight, too. Over a thousand dollars cheaper. Though it's quite nice, I do not see this new Sigma lens as a compelling value proposition for astrophotography work. I believe I'm going to be able to avoid a GAS attack on this one!


----------



## Jopa (Jul 19, 2017)

SecureGSM said:


> You have overlooked that the Sigma is virtually vignetting free at F2.8 and extremely low distortions and CA. That will definitely benefit IQ in outer areas of the frame. It is not as simple as one would thought. And no, you cannot compensate for the vignetting in post without IQ sacrifice due to increased noise levels.
> This lens is on my shopping list.
> 
> 
> ...



It seems like a great piece of glass. I live in a very "light-polluted" area, and never thought about doing astrophotography, but the video (it's so awesome) kind of pushes me to try it  Maybe one day...


----------



## SecureGSM (Jul 19, 2017)

Jopa,

this lens is super useful for low light crowd shots. Festivals, concerts, dance flow, etc.

see the image attached. shot at @16mm, 1-1.4 meter distance to subject only. in tight situation this lens can be instrumental in getting that very rare image.

P.S. note how the image is almost completely perspective distortion free for such a wide lens. I mastered the art of perspective distortion correction a few years ago . Seriously though - it is not a rocket science but properly corrected UWA images do look fantastic!



Jopa said:


> SecureGSM said:
> 
> 
> > You have overlooked that the Sigma is virtually vignetting free at F2.8 and extremely low distortions and CA. That will definitely benefit IQ in outer areas of the frame. It is not as simple as one would thought. And no, you cannot compensate for the vignetting in post without IQ sacrifice due to increased noise levels.
> ...


----------



## epsiloneri (Jul 19, 2017)

Jopa said:


> It seems like a great piece of glass. I live in a very "light-polluted" area, and never thought about doing astrophotography, but the video (it's so awesome) kind of pushes me to try it  Maybe one day...


Unfortunately, wide-field astrophotography is the kind of astrophotography that is most sensitive to light pollution. You would overexpose the background sky in a matter of seconds with this lens, and stars would be all washed out. For astrophotography, better use this lens when travelling to really dark locations. For light-polluted skies you are better off with high-power telescope astrophotography, e.g. of the planets or, for the more advanced, narrow-band imaging of nebulae.


----------



## Jopa (Jul 19, 2017)

SecureGSM said:


> Jopa,
> 
> this lens is super useful for low light crowd shots. Festivals, concerts, dance flow, etc.
> 
> ...



Great photo Alex! What's your secret sauce?  I saw how you fixed someone's graduation photo recently and it looked impressive.



epsiloneri said:


> Unfortunately, wide-field astrophotography is the kind of astrophotography that is most sensitive to light pollution. You would overexpose the background sky in a matter of seconds with this lens, and stars would be all washed out. For astrophotography, better use this lens when travelling to really dark locations. For light-polluted skies you are better off with high-power telescope astrophotography, e.g. of the planets or, for the more advanced, narrow-band imaging of nebulae.



I'm moving to a less urban area, hopefully it won't be as bad as where I'm now.


----------



## nubu (Aug 1, 2017)

Thanks! Here I did a more detailed comparison with the EF14/2.8II at several apertures: https://www.dpreview.com/forums/post/59871149


----------



## nubu (Aug 1, 2017)

Also here: http://www.canonrumors.com/forum/index.php?topic=33161.0


----------



## KeithBreazeal (Aug 9, 2017)

Thought I'd throw one of my test shots in here.
Resolution on this test shot was mighty impressive. The window pane grids are resolved but at the pixel level where the grid is the same width as an individual pixel. Lighting is moon light, f2.8, ISO 3200 and focus set on the stars. I was waiting for the clouds to move by that were partially obstructing the Milky Way but fired off some test shots.



Sigma 14mm f1.8 Art Canon 5D IV by Keith Breazeal, on Flickr

After the clouds cleared



Bodie Mine Head &amp; Milky Way 3330 © Keith Breazeal by Keith Breazeal, on Flickr


----------

