Tried to stack 30 minutes of Orion Nebula data but got a weird purple halo around the core

I was out last Saturday with my Canon T7 and 200mm lens, shooting 30 second subs at ISO 1600. After stacking in DSS I noticed this awful purple glow around the bright stars that wasn't in the individual frames. Turns out my UV filter was causing internal reflections - took it off and tried again on Monday and the halos disappeared. Anyone else run into filter ghosting ruining their widefield shots?

2 comments

2 Comments

brian32817d ago

Yeah, that purple halo thing is exactly what I dealt with last month using my old 135mm lens. I swapped my UV filter for a multicoated one and it cleared up almost completely, though I still get a tiny bit on really bright stars. Just ditch the cheap glass altogether if you're going after nebula widefield stuff.

riley_miller2517d ago

Funny enough, I learned that lesson the hard way too. Bought a cheap UV filter to "protect" my lens and ended up with purple blobs on every single star in my Orion shot. Looked like I was shooting through a cheap wine bottle. Ditching the filter completely made a bigger difference than I expected for my astro work. Now I just keep a lens cap on until I'm actually shooting and haven't had the issue since. Kinda embarrassing how long it took me to figure out that fix.