[graham.hobart (Graham stevens)]

Hello all, I took some subs of the Grus quartet the other night with the QHY 8 OSC using Nebulosity. At the same time ( hours apart) I took darks without moving anything, then flat frames using a light box. The flats on my screen showed a prominent dust bunny as well as the lights. I was hopeful this would be calibrated out but it has remained in the finished stacks.
I calibrated in Neb 3 then stacked the calibrated colour converted files in DSS.
Please tell me what I did wrong as the dust bunny is rather annoying.
I can post samples later when I finish work.
Cheers
Graz