
My first M31: beginner questions (capture and processing)
Hi everyone,
First of all, thank you to everyone who helped me on last week’s post about my very first polar alignment: it worked! I managed to shoot Andromeda and stack the frames. It’s very rudimentary, but I’m really happy: it’s my first deep-sky photo, and watching a galaxy appear is something else.
Gear: Sony A7III + Svbony SV555 APO (243 mm, f/4.5) on a Star Adventurer GTi. 58 × 30 s at ISO 800 (about 29 min total), stacked in Siril. No darks, flats or bias for this first one.
(photo here : https://ibb.co/7NK0gtB6)
I now have lots of questions:
Capture
- After my 2-star alignment, I set up the rest of my gear (intervalometer, dew heater). I don’t do it before because the cables tangle when the mount moves, and it also affects my manual focus. The problem is that the camera and lens (on the dovetail bar) are touchy and shift easily when I handle things, it’s almost impossible not to. Does that matter? When I recenter the second alignment star, it’s fine, I manage easily. But sometimes I have to do this setup after choosing my target (here Andromeda), so after the alignment: could touching the gear mess up the alignment? Do you have a solution? Should I fully tighten the clamp that holds the dovetail bar on the mount (even though it then can’t pivot at all)? Am I doing something wrong?
- To recenter my first alignment star, I sometimes move the mount directly using the angle adjustments rather than SynScan, because it’s faster. Is there any risk for the motors?
Darks, flats, bias
- I understand darks. For flats, I was told to use a white screen (my phone) in front of the lens, with a white T-shirt over it. My problem: I can’t see myself holding my phone over the lens for ten minutes to get my frames. How do you actually do it in practice? And about the white T-shirt: if I do this during my night session, it will look black. How does it work in that case, does it still work?
Processing
- I processed my photo in Siril (with an AI helping me through the steps). Which processing software do you use and like? Is Siril enough, or is there something better to bring out more detail? I have a Mac and a Windows PC.
- I’m a photographer otherwise and use Lightroom. How does astro post-processing work: should I use it in Lightroom like a regular photo (exposure, contrast, etc.), or is it a completely different job?
Thanks in advance, and clear skies!