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Dark Flats and Bias Frames

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Are you using a CMOS camera?  If so then my preferred method is lights, darks, flats and dark flats as I've read that CMOS cameras should use flats / dark flats instead of Bias.  However, having just read your profile, The Bias frames you take with a DSLR replace the dark flats.  no requirement to take both types. 


Edited by jacko61
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That's pretty close to correct.

Dark flats always work; bias frames are a bit simpler to manage. Some cameras yield very inconsistent results at the short exposure times necessary for bias frames, so for those, dark flats are your only option (the ASI1600 is one of those). But it's not CMOS vs. DSLR -- plenty of CMOS cameras, such as my ASI183, do just fine with bias frames. There have been any number of online flamewars about this but trust me, those are the facts of the matter.

Better yet, don't trust me, do your own experiments! I know I have, but that's just N=1, right?

I prefer the convenience of shooting a crap-ton of bias frames once or twice a year to the necessity of shooting a new set of dark flats every time I change my flats exposure time, but that's just me. I run my flats with Ekos set to "auto", so the exposure time does vary from session to session (though I've never experimented to establish how much this would affect the end result).

If you feel better about dark flats, go nuts.


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