Quote:
Originally Posted by UBoat
Hello Ray
Do you know if there has been much work done on the 'spatial noise' that might arise from stacking many 1 or 2 minute subs? IE noise introduced by the rotational alignment and stacking of successive images in which pixels may not quite line up, particularly square pixels. Does it degrade resolution more than stacking a few long exposures?
Peter
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you can use that form of variability to increase the resolution by using drizzle when you stack - it only helps if the image is undersampled, which will depend on the focal length, pixel size and seeing. probably worth doing in any case with your fairly small pixel count, since it is an excellent way to upscale images. Otherwise, there is no deleterious effect from many vs few subs that I know of and you would probably gain some resolution and definitely some dynamic range from multiple short subs.
edit: just had another thought - the Atik might not need to be cooled by a huge amount. Even if you can stabilise it at 10C say, you will get much more effective dark subtraction than at a varying ambient. You might not need much power at all to stabilise it at a moderate temperature rather than get it really cold - depends on whether they have used switch-mode control for the Peltier. Might be worth checking how much power it uses if you set a high temperature.