Hello, while I found a very insightful discussion here on flat fields for among others with a QSI/KAF 8300 I was wondering if anyone has some values for flats with a DSLR. I tried 10s/5s/3s/2s/1s against a flat filed panel but it's too much. The aperture priority setting doesn't give good results since I'm using an LP filter. Will try 1/2/1/4 etc. Anyone with a tip? Thanks a lot and CS! Best, Isa
PS: Below a picture of Orion Nebula taken with a Takahashi FSQ-85EDX with Extender 1.5x, LP filter, Nikon D800. As you can see, despite a master flat I still have this huge dark ring on the picture - masterdark and super bias are efficient so far. The core of the nebula is overexposed so will go easy on it next time, reducing exposure time to 180s (from 300s).