Quote:
Originally Posted by Bassnut
What do you mean by "better results", if you have vignetting, then the flats should show this, so that it can help fix it in the light exposure. The more vignetting, dust motes etc showing in the flat the better, its supposed to image the faults. The worse flats you can get is a uniform grey with no imperfections, thats useless, waste of iime, and of no "correction" value at all.
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That is my understanding too. I usually image for each colour until I can see the central dust motes for that colour; this also shows vignetting really well. It varies quite a lot really for each filter with exposure. I suppose I should use a numbers relationship but I go by what I can see in the flat image. This usually gives me a good flat to subtract away from the subs.