piperbailey•1mo agoTop Commenter

Tried stacking 30 minutes of Andromeda data and got way less than I expected

I was dead set on getting a killer shot of M31 with my DSLR and 200mm lens, figured 30 minutes of 30-second subs would be plenty. After stacking in DeepSkyStacker and processing in GIMP, the core was blown out and the outer arms were basically invisible. Turns out I needed way more total exposure time and better calibration frames, like at least 90 minutes from a Bortle 4 zone near Sedona. Anyone else mess up their first galaxy shot by underestimating how much data you really need?

3 comments

3 Comments

sean_cooper581mo ago

My first galaxy attempt was M81 with a 135mm lens and I only had 20 minutes of data. I was shocked when the arms barely showed up, it looked like a fuzzy cotton ball. The thing nobody tells you is that galaxies need way more integration time than bright nebulae. Bortle 8 skies near Phoenix didn't help either, that was a nightmare.

jade5171mo ago

@sean_cooper58 it's funny how that works, same thing happened to me with Orion Nebula versus a faint galaxy. Kind of like how in real life you can spot a flashing neon sign from blocks away but the quiet little coffee shop takes a while to notice. Galaxies are like those quiet spots in life that just need more patience and darker surroundings to really shine through.

victorh811mo ago

Wait, is that really the case with galaxies compared to brighter stuff like Orion? Back when I started out I thought 30 minutes of any deep sky target would at least show you the basic shape. I'd always hear people talk about integration time but I figured they were just being overly picky or had crazy expensive gear. Your post made me realize I was dead wrong about that. Looking at your Andromeda story and that M81 example makes total sense now, galaxies are way fainter than I gave them credit for. The Bortle zone thing is huge too, I was shooting from a gray zone thinking it was fine but apparently that's still too bright for faint outer arms. Gonna have to rethink my whole approach for galaxy season this fall.