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In my experience sampling is not as vital as it is made out to be. The earlier 11002 9 micron pixel camera worked well on any scope widefield or long focal length.
Also with drizzle integration in PI (I haven't used it yet) it would seem some resolution loss can be regained if you are oversampled.
I think the main thing with oversampling is losing some sensitivity. I doubt its 4X as your example suggests. I have never experienced that.
You do see a more impinging image with correct sampling.
Sampling theory also is not 2X for a good sample, its at least 2x. So 3X seems to work so for example a 3 metre focal length gives you around .66 arc sec/pixel with a 9 micron pixelled camera. That seems to work out pretty well. Not too bad in poor seeing and excellent in good seeing.
More of an issue for me is smaller pixels have smaller well depth which can lead to weak stars that are easily damaged in processing and you have to be more careful to retain colour, shape and look.
As a very rough guide I am finding that even with 77% QE and 305mm aperture at a fast F3.8 I still need to accumulate around 10 hours of data to get a decently solid signal to process well. 15 hours would be better. 30 is probably overkill and perhaps less than 10 hours from a really dark site but even then around 10 seems a good target exposure length for that setup.
I am not sure what you are referring to about sensors heating up? Is this to do with DSLRs? Astro CCDs are cooled with regulated temperature control and I don't see any evidence of them heating up. With DSLRs I think its more the batteries that heat up as they expend their charge.
Greg.
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