Astrophotography and landscape lens

zicklurky

zicklurky

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Chris
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Hiya,

I'm in the market for a wide lens I'll be using for widefield astrophotography as well as landscapes (and possibly northern lights next year). I was hoping you could sway me one way or another. I have a Samyang 14mm but it's too wide for me, so I'm looking at around 20-24mm on the wide end. And because of the night sky shooting, I'm looking at f/2.8 or faster. My list so far is:

- Canon 24-70 f/2.8 ii
- Sigma 24-35 f/2
- Sigma 24 f/1.4 Art
- Tamron 24-70 f/2.8

The Canon would be my first choice, but it is virtually double the price of all the others. The Sigma 24-35 looks interesting, although the corner sharpness doesn't look amazing at f/2, so it's going to need stopping down anyway. And then there's the 24mm Art! Decisions...
 
In theory they would all work as with wide angle you can keep the shutter open for quite a long time without star trails. My best photos have been wide open at f1.2/4 in locations with no light pollution where this gives an incredible number of stars visible in the shot.
 
I don't know much about astrophotography, well make that nothing, but have you considered the sigma 18-35mm f1.8 art, it covers the focal length your looking for and is by all accounts a cracking lens. I have seen some astro shots with it, they looked impressive to me but as I said I know I don't really know what I'm looking at. Good luck in your hunt.
Derek
 
You mention you also want it for landscapes. Assuming you've still got a 5d3 and so can push the ISO a bit I'd consider a 16-35 F4. 24mm gives you around 25 secs exposure the 16 end would give you 30 but might be too wide for you. The lens is a belter if you're in the market for a wide zoom that can be used for astro.
 
If you're using a lens around 24mm and upwards then for astro the faster the better. 24 mm only gives you around 20 secs on the 500 rule to avoid trailing so having a f1.8 or f2 would be an advantage. If you have a tracker then lens speed doesn't really matter too much. If you're planning a lot of astro then a tracker is the way to go especially if you eventually plan on using longer focal lengths. I've got 8 minutes at 17mm with mine without really spending too much time on aligning it.
 
Yeah sorry forgot to mention it's on my 5D3. I'm torn on the tracking idea, which would mean composites if there's landscape in the frame, instead of a single image.

I'm swaying towards a zoom as it's more flexible. I'll go though my image history and see how much I shoot 35-70mm. Also have a think about the 16-35 f/4.
 
zicklurky said:
Yeah sorry forgot to mention it's on my 5D3. I'm torn on the tracking idea, which would mean composites if there's landscape in the frame, instead of a single image.

I'm swaying towards a zoom as it's more flexible. I'll go though my image history and see how much I shoot 35-70mm. Also have a think about the 16-35 f/4.
Click to expand...

Well that's the 18-35mm out then :)
Didn't realise you are on FF. :oops: :$
 
You will get better final images by stacking several images. One stack for the foreground and one stack for the sky and then blending. If you're taking at say ISO 3200 then the stacked noise will be less also. If you go for one of the cheaper lenses you could buy a tracker with the savings. I realistically can't see me taking another single image astro shot now I've got a tracker. Bit of a learning curve but the results are worth it.

This is my first effort with the tracker. Again depends on how much you will use it. Obviously need the weather. The one I've got also doubles as a time lapse head which is something else I want to do.

https://www.talkphotography.co.uk/threads/m42-nebula.621136/
 
Gaz J said:
You will get better final images by stacking several images. One stack for the foreground and one stack for the sky and then blending. If you're taking at say ISO 3200 then the stacked noise will be less also. If you go for one of the cheaper lenses you could buy a tracker with the savings. I realistically can't see me taking another single image astro shot now I've got a tracker. Bit of a learning curve but the results are worth it.

This is my first effort with the tracker. Again depends on how much you will use it. Obviously need the weather. The one I've got also doubles as a time lapse head which is something else I want to do.

https://www.talkphotography.co.uk/threads/m42-nebula.621136/
Click to expand...

Apologies for the mini hijack. Which tracker do you use Gary and would you recommend it?
The Missus is into her astrophotography and has a birthday coming up ;)
 
I've got a Skywatcher Star Adventurer Astro Kit. Have only used it in anger once due to weather but have spent a bit of time trialling it when some stars were visible. I think it's a reasonably priced entry into the realm of tracked astro. I only ever intend to use the cameras and lenses that I own. If your wife is planning to use a telescope that possibly the weight limitation would become an issue. I think it's got a weight limit of 5.5 kg. I've used it with my 6 D and a 100-400 MkII for 120 sec exposures with good results and my mate has used a 300 f2.8 and 5D3 on it.
 
Gaz J said:
I've got a Skywatcher Star Adventurer Astro Kit. Have only used it in anger once due to weather but have spent a bit of time trialling it when some stars were visible. I think it's a reasonably priced entry into the realm of tracked astro. I only ever intend to use the cameras and lenses that I own. If your wife is planning to use a telescope that possibly the weight limitation would become an issue. I think it's got a weight limit of 5.5 kg. I've used it with my 6 D and a 100-400 MkII for 120 sec exposures with good results and my mate has used a 300 f2.8 and 5D3 on it.
Click to expand...

Sounds like a good plan, I may go this route. And get a 24-70 f/4. This way I can use my 77mm filters as well. Thanks!
 
When I was shooting the lights in Iceland last year I was using a canon 16-35/4 and a Samyang 24/1.4 on a 6D. I found myself wishing for a 16-35/1.4 as the 24mm was often not quite wide enough.
 
On the other hand this is 8 seconds at f1.2
ImageUploadedByTalk Photography Forums1460795603.656672.jpg
 
Gaz J said:
Are you trying to point out the difference in the number of stars between the two exposures or something else? Mine is a 1500 pixel crop out of the centre of a 20MP image.
Click to expand...

Hi Gaz, just illustrating the impact of wider aperture requiring much shorter exposure - if maths is right 8 mins at f5.6 is about the same amount of light as 8 secs at f1.2. Taking a closer look comparing our examples also shows the benefit of a tracker as your stars are pin sharp whereas mine have small trails even with 8 seconds. :)
 
to illustrate here is a roughly 1500 px crop from my example for comparison
 

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newbie1 said:
Hi Gaz, just illustrating the impact of wider aperture requiring much shorter exposure - if maths is right 8 mins at f5.6 is about the same amount of light as 8 secs at f1.2. Taking a closer look comparing our examples also shows the benefit of a tracker as your stars are pin sharp whereas mine have small trails even with 8 seconds. :)
Click to expand...

I think your equivalent exposure at f1.2 would have to be around 20 seconds.

f1.0 -----------15 seconds
f1.4 -----------30
f2 ------------ 60
f2.8 ------- 120
f4----------- 240
f5.6 ----------480

I wouldn't use 8 minute exposures for wide field astro photography as any light pollution starts to make itself apparent. It was an experiment to see how long I could get without spending a lot of time polar aligning.

Focusing is my biggest issue. To keep as much stability as possible I extend the tripod only enough so that I can look through the polar scope when sitting on a small stool. This then makes it harder to align and focus even in live view. One of the reasons I went for the 6D was that it has wireless. What I do now is to put my iPad on a second tripod and stream the live view to the iPad. I find this makes it easier to focus.

Its definitely a learning curve and I have learnt a great deal in the few weeks that I have had the tracker. Hopefully all the messing about will bring dividends when I go out in the future. in my view its better to practice when it doesn't matter than spend time faffing about when the sky is clear.
 
mrgubby said:
When I was shooting the lights in Iceland last year I was using a canon 16-35/4 and a Samyang 24/1.4 on a 6D. I found myself wishing for a 16-35/1.4 as the 24mm was often not quite wide enough.
Click to expand...
I use the Samyang 14mm f/2.8 for Astro, works very well.
 
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