I finally figured out why my Orion Nebula shots looked like mush compared to the guy next to me at the Grand Canyon star party | Astronomy Photos - Rigidtalk
I finally figured out why my Orion Nebula shots looked like mush compared to the guy next to me at the Grand Canyon star party
Last month I drove out to Mather Point on the South Rim with my new telescope and spent 45 minutes trying to get a clean shot of the Orion Nebula. Every picture came out as a blurry purple smudge, and I was ready to blame my gear. Then a retired guy named Walt set up next to me and his shot on a cheap DSLR looked ten times better. He asked one question: was I stacking frames or just taking single shots? I had no clue what he meant. Turns out you take 20 or 30 short exposures and let free software like DeepSkyStacker line them up and average out the noise. My single 30 second shot was full of sensor heat and sky glow, but stacked 8 second frames cut all that junk out. I tried it the next clear night in my backyard in Flagstaff and the difference was nuts, actual gas clouds and the Trapezium stars split apart. So who else here started out shooting one long frame and wishes somebody had told them about stacking sooner?
The stacking thing goes way deeper than just cutting noise too. Once you start taking calibration frames, darks, flats, bias, it gets even better. Darks cancel out the hot pixels that show up as those colored dots, and flats fix the weird dark corners you get from the telescope itself. I skipped flats for months and couldn't figure out why one side of my Andromeda shot was always darker, turns out it was dust on the sensor and a flat frame would have wiped that right out. You don't even need a cooled camera for it to work, just keep the darks at the same temp and exposure as your lights. Walt basically handed you the keys to the whole hobby in one question.