Stacking 400 photos fixed my blurry nebula shots, wish I knew this a year ago

I spent 14 months taking single long exposures of Orion and wondering why they looked so soft compared to the ones posted here. Then a guy at the local club meetup in Tucson told me to stop fighting light pollution and just take 30 second subs, then stack them in DSS. I tried 400 frames on the same target last Tuesday and the difference was night and day. The background noise just melted away. My question is, how many frames do you normally need before adding flats and darks starts mattering more than just raw count? I skipped calibration and still got decent results.

2 comments

2 Comments

dixon.spencer19d agoTop Commenter

Man that first time you see the stacked result is such a kick in the gut, like why didn't anyone tell me this sooner. I remember doing the same thing with Andromeda, 60 second subs for months and just getting this mushy grey blob. For flats and darks, I'd say once you hit around 100 frames they start making a real difference, especially flats since they fix that dusty vignetting in the corners that gets more obvious the more you stack. I skip darks most nights now if I'm lazy and honestly the flats matter way more, so you're probably fine sneaking past calibration for a while.

gavin_kelly9119d ago

Darks get way more flak than they deserve. Yeah, flats fix the dust donuts and vignetting, but if you are shooting in warmer weather or your camera runs hot, those darks are the difference between a clean background and noise that looks like static on an old TV. I tried skipping darks for a week once to save time and my Ha shots came out with this weird banding that flats could not touch. Plus, your darks library gets reused for months if you keep the temp and gain the same, so it is a one-time cost. I get that 100 frames feels like a lot, but I would rather spend an hour on darks than spend three hours trying to clean up the mess in post-processing later.