M31

Cheshire Cat

6136

Deep Sky

Sep 22nd, 2025

1400

NGC 206NGC 205NGC 221NGC 224

Resolution:: 6763x4375 px
File size:: 24261 KB

Show astrometry on hover

Technical information

Telescope/Lens: TTArtisan 500mm f/6.3 ED Lens
Camera: Sony A7 IV
Mount: Sky-Watcher Star Adventurer
Software: Siril, GraXpert, StarNet++, Adobe Photoshop

Location: Saint-Petersburg, Russia

Light pollution

Yellow, Bortle 5 zone

Date taken: Sep 19th, 2025

Exposure

210 × 30″ · ISO/Gain: 4000 · Sep 19th, 2025

Total exposure: 1 h 45 m

Comments

Oleg Novoselov

Can you post the total amount? I really want to see how the lens performs.

Sep 22nd, 2025

Cheshire CatReply to Oleg Novoselov

I would have shared them. But while copying the source files from one drive to another, I made the first mistake. Then I made the second mistake when I copied the wrong folder from the camera again and decided to update the firmware with a card format. In short... The source files are gone. The first source files I lost.
The previous images should have stacked versions.

Sep 22nd, 2025

Oleg NovoselovReply to Cheshire Cat

The lens is good for its 22k price, plus it's full-frame, so I wanted to check the chromatic aberration and distortions. Please share what you have, a single shot and some stacked version, thanks.

Sep 22nd, 2025

Cheshire CatReply to Oleg Novoselov

Oleg, this is all that's left. ((
Open the original, you can see the glitches there.

Sep 22nd, 2025

Nickolay

Just what the doctor ordered) good job.

Sep 22nd, 2025

oeswww

Is this an issue with a missing coma corrector or an incorrectly chosen back focus?

Sep 22nd, 2025

Cheshire CatReply to oeswww

I don't know what kind of corrector can be inserted between the lens and the camera. Does such a thing exist?
At f/8, the lens will already deliver better sharpness, but it's a bit dark.
I'm shooting without a guide, about 20-30 minutes of frames went straight to the trash.

Sep 22nd, 2025

oeswwwReply to Cheshire Cat

Overall, this telephoto lens has a lot of lens elements, so in theory, coma correction should be present, but maybe it isn't. I can't even find in the specs what its aperture is...

Sep 22nd, 2025

Cheshire CatReply to oeswww

The glass is decent, but don't expect any magic for 20,000 rubles.
80mm aperture, if we go by the formula.

I'm even willing to put up with seagull-shaped stars in open clusters.
I'd love to shoot more often, but it usually ends up being a weekend night trip out of town and then heading back home.

Sep 22nd, 2025

Ryjov AlekseyReply to Cheshire Cat

For such a glass, the result is excellent))

Sep 23rd, 2025

Cheshire CatReply to Ryjov Aleksey

Thanks))
I think the camera still has a lot of potential to bring out more detail.
But there's a catch: on Sony cameras, you can't use exposures longer than 30 seconds, because forced noise reduction kicks in.

Sep 23rd, 2025

Ryjov AlekseyReply to Cheshire Cat

Yes. Probably 30 seconds is a bit short, but the object is bright enough. I think it should work for M33 as well.

Sep 23rd, 2025

Cheshire CatReply to Ryjov Aleksey

I haven't posted last year's practice results yet.
I've gained a bit more experience and plan to go through all the basics this autumn-winter, like the Pleiades, M33, large bright planetaries, and reshoot M81-82.

Sep 23rd, 2025

Ryjov AlekseyReply to Cheshire Cat

Yes, the most important thing is learning how to process. I still don't really know how to do it properly.

Sep 23rd, 2025