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Old 19-09-2017, 12:03 PM
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Merlin66 (Ken)
Spectroscopy Wizard

Merlin66 is offline
Join Date: Oct 2005
Location: St Leonards, Vic
Posts: 7,583
Yes, but....
""the size of the airy disc is determined solely by the aperture of the telescope""

you should say "the angular size...." the seeing disk still dominates.
If you have say, excellent seeing conditions of 2 arc sec.
The seeing disk (FWHM) would be:
400 fl = 3.9 micron
1250 fl = 12.1 micron
2500 fl = 24.2 micron

Lucky fast frame imaging (ie solar etc.) can effectively freeze the seeing and give much better results.
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