Quote:
Originally Posted by rogerg
I probably should know the answer to this, but feel it's worth a discussion to broaden my knowledge.
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Resolution is a factor of focal length and pixel size, to my knowledge. While possible to choose a combination of long focal length and small pixel size (perhaps to reach 0.5" for example) this would result in a horribly poor quality image. But in practice is there a way for 0.5" to become usable?
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Regards,
Roger.
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Dear Roger.
I agree with most of what the others have said but am just commenting on the point above. Theoretical resolution for a scope is proportional to the scopes diameter and the wavelength of the light. Focal length has nothing to do with it. Otherwise a tiny scope with a very long focal length would give hubble level resolution.
Longer wavelengths have lower resolution as well but for light this isn't terrible important (For radio astromony it is very important)
Practically of course other factors limit the resolution as you have discussed. I image a 0.78arcsec/pixel but often will bin 2x2 expecially for photometry of dim objects just to keep the file size down. FWHM for me is rarely better than 2arcsec and I live at 1100m altitude. I would be supprised if anywhere in Australia has much better. The AAO at a similar altitude to me is has similar seeing.
Cheers
Terry