I was stacking my astro photos wrong for a full year

I kept getting these weird, blotchy results in my deep sky images, especially on faint nebulae. I was using DeepSkyStacker and just dumping all my light frames in, about 200 shots from a night in Joshua Tree. My buddy, who runs a local astronomy club, finally looked at my data and said, 'You're not checking your FWHM scores, are you?' I had no idea what that was. Turns out, I was stacking every single frame, even the ones with bad atmospheric seeing that were blurring the stars. He showed me how to sort by that score in the software and reject the bottom 20%. The very next stack I did on the Orion Nebula was cleaner than anything I'd made before. The dust lanes were actually sharp. Has anyone else had a 'duh' moment with a basic stacking setting they overlooked?

3 comments

3 Comments

the_anthony1mo ago

So it actually makes a difference?

the_anthony1mo ago

Yeah, it's the little things that add up...

murphy.blair1mo ago

But I've seen those little things not add up at all, @the_anthony.