Quote:
Originally Posted by ptc
you really need to measure it to know how much difference the extra cooling will make. In that data I posted is some measured data from Tim Khan's ML8300 running at -25C with and without light flood (Page 17)
He has very low read noise so his cooling at -25C and no light flood is sufficient for a 400 second exposure
of course none of this matters with bright objects shot in bright skies with broadband filters. The background signal levels are way larger than the noise contribution from dark signal components.
as far as libraries go: I have seen that the ambient temperature can affect the bias level a tad. Since you should NOT use dark scaling when using the light flood, you might want to take darks at extremes of ambient temperatures encountered during a year of imaging. There's really no reason to toss them unless you are picking up more costmetic defects or you have a long term bias drift issue which I doubt.
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Ok, so:
1) Colder the better is valid but most useful under dark skies where it is advantageous and noticeable.
2) A library of darks is usable for quite a while (even years?)
So perhaps I should keep the set of -30C darks for spring/summer and do a new set of -40C darks for use in winter?
Mike