I am experiencing really nasty halos around some stars that I'm sure is coming from my narrowband filters.
These halos are noticeable in single subs, and are very pronounced when stacked. It's happening for stars that aren't even that bright!
Is this to be expected with the filters that I'm using or is there something that I can optimize to reduce these?
Any advice appreciated...
SharpStar 150HNT (F2.8, 420mm focal length hyperbolic newtonian)
Optolong 6.5nm Ha, Oiii and Sii filters
The following is an Oiii master stack of 50*300s subframes (gain 100, offset 10, -20C)