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Old 29-01-2014, 10:57 PM
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RickS (Rick)
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Join Date: Apr 2010
Location: Brisbane
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Quote:
Originally Posted by Shiraz View Post
As I understand it, once you have reliable set of darks (for which you might need overscan compensation), the issue is dealt with - all you need overscan for is to get the right dark current to scale and subtract. Bias drift in the lights will only show up as a variable offset, which can be easily dealt with - is this a reasonable statement? EDIT: of course this only applies to pretty pictures, not science data - overscan compensation would be essential for some forms of photometry.
Ray,

I do overscan calibration of all my data - calibration frames and light frames. PixInsight subtracts the median of the overscan region from all of the data pixels and then everything else happens as usual. This is intended to remove any bias drift from the data before it is processed.

Cheers,
Rick.
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