The feedback on my nebula stack that actually helped

I posted my Orion Nebula last month and someone just said "your stars look bloated, try fewer exposures next time." I was doing 60 second subs because that's what a tutorial said. Cut it down to 30 seconds and the stars came out way sharper. Also stopped using the cheap focal reducer I had on there. Got a real 0.8x reducer instead and man, the difference is night and day. Has anyone else gotten a simple tip that totally changed their processing?

2 comments

2 Comments

david_rivera425d ago

Yeah so my buddy Mike had this exact thing happen with his Andromeda stack. He was doing 90 second subs because some YouTube guy swore by it and his stars looked like little footballs. Someone just told him to check his guiding RMS and drop exposure to 45 seconds. Completely fixed his star shapes overnight, no joke. He also had a cheap UV filter on there that was adding weird halos, pulled that off and suddenly his processing actually worked, crazy how one tiny thing can mess everything up.

hollyg5925d ago

Hold on though, 45 second subs on Andromeda sounds like a good way to get nothing but read noise and a really dim target. If your buddy was getting football shaped stars at 90 seconds, that's a guiding or balance problem, not an exposure length problem. I run 120 second subs on my 8" SCT with a cheap guide scope and my stars are round as pennies, you just gotta dial in your RA and DEC corrections right. Plus pulling the UV filter off could just let more light pollution hit the sensor, making gradients worse and killing your contrast on that faint outer halo. You can't fix bad guiding by dropping exposure time, you're just hiding the real issue with a crutch.