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Old 23-11-2013, 11:53 AM
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avandonk is offline
Join Date: Aug 2005
Location: Melbourne
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Completely different scenario. Planetary imagers are just recording the tiny peaks of the Airy Disc. They are recording quite bright images that can be temporally separated.

At f40 the Airy disc is about 50 micron. Please explain!


Originally Posted by Satchmo View Post
To be fair the error on Hubble mirror was 1/2 wave RMS - much greater than you will find on a lower end typical consumer scope .

There has been a thread on this before - but planetary imagers need focal lengths of 5 to 15 meters to literally oversample the airy pattern with pixels to exploit every bit of quality in their optics and detail possible in the image. Its all to do with pixel scale versus airy disc size vs. seeing . I think there would be few deep sky imaging rigs exploiting optical quality fully , but I do feel that the better the optics , the less havoc tilt and defocus of the wavefront due to seeing , will have on the FWHM. There is no doubt that the guys with known good optics that are well mounted and guided are coming up with the premiun images.
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