p.1 #1 · Recommendations for a higher focal length lens for nebula shots beyond my wide-angle kit?
Hi Sony community! As an amateur night sky chaser with my Sony a7 IV, I've got a great wide-angle setup for Milky Way and broad starfields, but I'm looking to step up to nebulas and deeper sky objects.
What lens in the 35-50mm range (or similar) would you recommend for better detail on things like the Orion Nebula?
Needs good coma control and fast aperture for low light budget around $800-1200. Sony native preferred, but third-party is fine if it performs.
I built my current kit using lenskitpicker.com, and it's got these fantastic visuals that let you see your lens coverage like a pro super useful for spotting gaps in focal lengths for astro work.
Here's my kit link: https://lenskitpicker.com/kit/c5d6ff. Attached some screenshots of the viz and UI the interactive diagrams are a game-changer for planning. What do you all think?
p.1 #2 · Recommendations for a higher focal length lens for nebula shots beyond my wide-angle kit?
Voigtlander 35/2 APO. I use it, the Voigtlander 65/2 APO. They are reasonably fast, but very well corrected wide-open. You will need a tracker for both. If you focus right, the stars will be pinpoints across the entire frame.
The 35 is fairly compact, but the 65 is a bigger lens, so a beefier tracker than the MSM Nomad (or equivalent light tracker) is recommended, or use shorter exposure times.
The 65 has a long throw, but the sweet spot (which is very sweet) is narrow, so you need good night focusing skills to get the best from the lens. A trick that I learned with my Sigma 14/1.4 is to focus in the mid-field and very gently noodle the focus in the extreme periphery to remove any astigmatism. It works surprisingly well. Both Voigtlanders can be forgiving even with poor night focusing skills, but the recommended approach could also work with your 14/1.8, which is not flat field wide open.
p.1 #4 · Recommendations for a higher focal length lens for nebula shots beyond my wide-angle kit?
As I think 50mm may be a bit short for Orion so I invite you to check out my 6 shot album on Flickr, all taken with the Sony 70-200 @ 200mm except the Whirlpool Galaxy with the 100-400 @400mm. Processing info is stated as well. https://www.flickr.com/photos/ritchbledsoe/albums/72177720318750963/
p.1 #5 · Recommendations for a higher focal length lens for nebula shots beyond my wide-angle kit?
The Rokinon 135/2 is the standard recommendation for astro. That is reasonable if you just plan to shoot astro as it is MF and fairly cheap. I personally use the Sony 135/1.8 GM, it has excellent auto focus for other uses as well. Optically excellent, that should be in your reach on the used market. Sigma and Viltrox also make 136/1.8 with AF. I think the Sigma and Viltrox are considered better bang for the buck, I personally don't believe they would match the Sony GM for AF speed and accuracy.
p.1 #6 · Recommendations for a higher focal length lens for nebula shots beyond my wide-angle kit?
I use three lenses for astrolandscapes with my a7rv.
- Sony 20/1.8G - good lens, but not perfect. I use it wide open.
- Sony 50/1.2GM - good around f/1.8-2.2 depending on your quality needs - my test raws (converted to DNG for smaller size) are here: https://jtra.cz/foto/20240404-astro-test-50gm/
- Sigma 135/1.8 - there is some lateral chromatic aberration, it is not perfect, but I had it already before I started astro. I don't stop it down for astro. Usually Samyang/Rokinon 135/2 is recommended.
For mid focal range, I have considered Voigtlander 35/2 APO, but I did not like high vignetting. I have also considered Sigma 40/1.4 which is known for sharpness, low vignetting and low aberration, but landscape astrophotographers I chatted with were complaining about it not holding focus distance when they change altitude angle for multirow panoramas. It is also very heavy. I would not be lugging it for any other purpose while 50GM is dual use for me. So 50GM won. It works great for portraits (I used 55/1.8Za before, that one has high coma).
Astro is most demanding discipline for the lenses because you want perfection wide open. You will run into lenses that will be perfect for everything except for astro. I have returned 35/1.4GM that was ok for everything except for astro (right side was slightly not in focus at f/1.4, this would not matter for portraits where subject closer to the center, this would not matter for landscapes where stopping down would make the side more focused).
I have also returned 14/1.8GM that had left side bad until f/5.6. My 24/1.4GM is just not great for astro (even after trip to Sony service) so I use 20G instead.
As you can see the copy to copy variation will be your concern. Lenses that are not perfect new will be unlikely to be fixed.
I have videos for all of these how I took them, exif info and often how I processed them. They are in Czech language with corrected English subtitles. Some later (non-astro) videos have dual audio with added English voiceover track (my voice, no AI). https://www.youtube.com/@fotovylety/videos
p.1 #7 · Recommendations for a higher focal length lens for nebula shots beyond my wide-angle kit?
I agree with 50mm being on the very short end for nebulae. Is there a strong reason for you not to consider something longer? Personally I regard 135mm as the minimum and would not bother with anything shorter. It is doable, sure, but you will miss out on a lot of detail.
Here is an Orion image I worked on with the Sony A7III and the Sony 135mm F1.8 GM. While this is much longer, I still wished I would have had more reach - also had to rename this to 'Greater Orion Region' because Orion itself looked fairly tiny in the vast frame. https://www.astrobin.com/azjk6h/?nc=user
The 135mm GM is a great astro lens which for some reason is rarely mentioned in the context of astro. I stop it down to F2.0 for almost perfect corners. Granted, it is a bit more on the expensive side.
Now if you insist on going with a 35-50mm lens, the Voigtlδnder 50mm APO f/2 is excellent. I have been using this for years for milky way mosaics. No need to stop down and manual focus is very precise. This lens would nicely fit into your budget.
