I have a bunch of subs of the Helix Nebula taken with a cooled DSLR and a CLS filter. I am having terrible trouble getting it colour balanced. it is way too blue. I tried in PShop and also wipe and colour bias in Star tools. If I get rid of the cast it loses the faint outer rings.
Help please.
I can post it but it's a TIF currently so its a big file.
Graham.