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Old 21-07-2014, 04:34 PM
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Shiraz (Ray)
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Join Date: Apr 2010
Location: ardrossan south australia
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Quote:
Originally Posted by RickS View Post
Ray,

Have you seen the new PI Superbias process? It uses multiscale analysis to isolate large scale structures and generate a "noise free" master bias from a lower quality master. Perhaps Superflat is next

Cheers,
Rick.
Yes, Marc pointed it out.

definitely seems to be related. I got the impression that the basis for the superbias approach is that bias will vary predictably (in a spatial sense) and that any abnormal pixel-to-pixel variation must be down to read noise - and hence removable. In the case of flats, the pixel-to-pixel variation can be FPN, flat read noise, shot noise or (darkshot+readdark+readbias) from the dark cal - this may be much less amenable to filtering. We live in interesting times though and it is good to see some formal optimisation of the processes we use.
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