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Old 24-11-2013, 10:29 AM
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Peter Ward
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Peter Ward is offline
Join Date: Dec 2007
Location: The Shire
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Originally Posted by Shiraz View Post
hi again Greg.

Tight stars do not of themselves indicate high resolution. Sure the optics must be good enough for seeing limited performance, but the star tightness is then mainly a function of the sampling......

Regards Ray
You conveniently ignore the physical size of the airy disk with this approach.

Airy disk size (assuming perfect optics) is purely a function of F-ratio.

At F8 the light is being spread over 10 microns. At F3.8 this contracts to 4.7 microns.

Not withstanding sampling, assuming the same aperture, you are concentrating the same flux into fewer pixels....
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