Let’s say I have a stack from 60×180s subs and a stack from 30x 60s subs. Does it make sense to stack the two master stacks together? Or will the 30x 60s stack degrade the image quality and am I just better off using the 60x 180s stack only?
Don’t combine stack like that.
You need to use HDR software
You may preprocess and process separately each exposure sequence, in Siril, and try to composite your images with layers in Gimp
I have 200x 10min subs with a duo narrowband L-Ultimate HaOIII 3nm and an Altair SIIOIII 6nm. My goal is to make an SHO image by splitting the rgb channels and recombine as SHO. I first stack the HaOIII and the SIIOIII separately. But there are 2xOIII channels and I want to stack them to improve SNR and lower the noise. So can I do that with a simple stack?