Sony FE 20mm f/1.8 G - Astrophotography Review 

Glad it was helpful! I couldn’t find the type of reviews that I would want to see before buying gear, so I thought I’d just make ‘em.

@@FerventAstronomy Happy you did! Would love a 24mm 1.4 GM one too! I have a copy performing worse then my 20mm 1.8 G, so I am a bit baffled. Would love to know your take on this one :) Thanks again

I took samples and some to-camera intro footage this summer, just need time to finish it off

@@FerventAstronomy Awsome :) I`ll keep an eye out for it. Have a great week end!

Thanks! I'm working on it, haha. I spent the summer recording a bunch of intros and taking samples, the real hard part is finding the time to put it all together and do the screen recording portion.

Thanks for the kind words, I hope you found the video useful. For time lapses I use a wired shutter release, with the camera in continuous shutter mode. In manual mode I set the shutter speed (in this case 20 second exposure), aperture, and put the ISO on auto. Then I lock my shutter release in the on position and just let it go.

@@FerventAstronomy Awesome! Ill have to look into what a wired shutter release is. Thanks for the reply!

It’s basically a cable that you plug into the camera, and it’s attached to a little remote that has a shutter button and typically a locking mechanism to keep the shutter pressed.

Sounds great!

Thanks much! My goal is to take all the guesswork out of how a lens will perform for astro :D

I’m trying to get around to a comparison video, but for my part I sold my Sony and chose the Sigma

@@FerventAstronomy Would love to watch the comparison video. I was leaning towards the Sony but now I'm not sure lol. Can you tell me your main reason for the switch?

While the Sigma is capable of producing worse astigmatic aberrations, it’s only on the brightest stars. These can easily be corrected with a few clicks during post processing. For me this is a worthwhile trade off as one gains a faster aperture as compared to the Sony, but perhaps more importantly also a more even reproduction of apparent star size between the centre and edges of the frame. This is useful for me because it makes for more pleasing time lapse videos, even though one has to live with the extreme astigmatism on the brightest stars in these scenarios

@@FerventAstronomy I really appreciate the detailed response. I do like to capture milky way time lapses so plus points to Sigma for that. Still a tough choice between the two. Looking for forward to that comparison video!

I appreciate that!

That time-lapse was made using the lens being reviewed

I didn’t actually do a good job documenting it, which is a bit unfortunate in hindsight. But I essentially built a light-tight baffle around the optocoupler inside the shutter mechanism itself which allows the metal frame to which the curtains are attached to slide under the baffle in a light-tight way. It was tricky because this mechanism needs to slide through the optocoupler for it to do its job and allow the camera to function. I’m actually surprised by how well it has held up, because it was an extremely finicky and impractical workaround. In 2024 and beyond it makes more sense just to modify an A7R4 I’d reckon.

@@FerventAstronomy thank you, amazing that you managed to baffle it in a way which does not obstruct the shutter blades. I will have to have another look inside that shutter since I already have a modified A7RII. I also have a full spectrum GFX100s and they also suffer this issue only the shutter is fully closed and you cannot easily track where the optocoupler location. Due to cost I'm hesitant to dismantle that shutter.

That’s a bummer about the Fuji. The whole ordeal taught me to check what Kolari Vision has to say about any given camera before doing a conversion. They’re the most reliable among the well known brands in this regard, in my experience.

@@FerventAstronomy plenty of warnings on their site nowadays, not when I did my A7RII conversion 6 or 7 years ago. Also, no warning about the GFX100S.

That’s a bummer, guess it’s probably not a very common camera for that type of mod. You can also try cross referencing with LifePixel, but again if no one’s ever sent one in they wouldn’t know either. Too late for that either way, so, bummer

Hi, I missed your comment sorry about that. if your camera is unmodified, and you can’t achieve infinity focus, there might be a defect in the lens. You should be able to manually focus to infinity, or a little bit past infinity. This allows you to get the smallest star possible. If you can’t do this and your camera is modified it’s because the refractive index of the camera has been changed. If your camera is unmodified hopefully you will be able to send the lens back for warranty repair.

I'll check it out if I get a chance

Same here

given my experience filming aurora, you should use the widest, fastest lens available. In this case that would be the new Sigma Art 14mm f/1.4 DG DN. Even then it may not be fast enough to capture 24p footage using a 360º shutter

@@FerventAstronomy the 24 1.4 Samyang was plenty fast enough but just not sharp enough. I went with the 14 1.8 as one came up for the right price. Hopefully I’m lucky enough to catch them again and if so I’ll report back on its abilities

@@user-ey8rs2bm1q Glad to hear you found a good deal, the GM 14mm f/1.8 is great. I've had mixed results filming aurora real-time, as even at 24p I've found the slowest possible shutter speed just doesn't cut it and I have to fall back on time-lapses instead. It has me considering getting an A7S III. What camera are you using?

@@FerventAstronomy A7Sii but originally I filmed on a Samyang 24 1.4 hoping the difference in 1.4 > 1.8 isn’t the difference however I must say i was extremely lucky to have a KP 5-6 for the nights I filmed

Zooms are not ideal for astrophotography. As far as primes go, I’ll be posting reviews of the two fast 14mm lenses available for Sony, so you’ll have samples from each one to help you make an informed decision.

@@FerventAstronomy The new Sigma Art 14mm f1.4 looks pretty compelling up against the Sony 14mm f1.8 GM but the Viltrox 16mm f1.8 is now in the mix too and I’m wondering how it compares to the premium models.

I’m working on a comparison video, but spoilers: I sent the Viltrox back to Amazon. The Sigma and Sony remain bunked up together in my camera bag.

@@FerventAstronomy I also returned the Vitrox 16mm... I have a few uses cases... didn't get to check the astro performance. The AF out of the box was junk. Worst modern AF lens I've ever bought. 😢

@@bradl2636 Definitely an effort, they have a little ways to go maybe

For my work it’s perfectly cromulent, so for the moment it’s the one in my bag.

Thanks, I’m thinking about purchasing an a7IV for nightscape astro and I’m new to Sony. Just trying to understand what the preferred lens options are. Thanks again for the vid.

Hopefully it helped you decide what might be best for you. Nothing is perfect, at least at the moment, and they each have their strengths

Most modern cameras do spatial filtering, although they differ in how they handle it. Older Canon DSLRs are some of the only cameras that didn’t cook their RAW files, which is one reason they remain popular choices. That said, spatial filtration isn’t that big a deal in newer cameras. At regular viewing sizes you’d never notice, and most people wouldn’t notice one way or the other unless told something was happening.

@@FerventAstronomy Can you suggest best appropriate Canon bodies for astrophotography? I hear 6D for FF is well regarded?

A 6D is a good camera yes. The weak point of that system is lenses. But for use with an astrograph it’s a good workhorse.

@@FerventAstronomy Thank you for taking the time to answer my questions.

Happy to help, that’s why I’m making these videos 🙂