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Old 27-05-2014, 09:26 AM
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Shiraz (Ray)
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Join Date: Apr 2010
Location: ardrossan south australia
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Quote:
Originally Posted by Merlin66 View Post
How do you actually measure the SA of your objective??
Do I need to do a focused star image test with the outside annulus, the central region being covered and compare the focus position with a similar test just using the central region??
maybe the easiest way is to get Suiter's book and compare star test images with his illustrations - it's not precise by any means, but can at least give you a ballpark idea of what your optics does.
http://www.amazon.com/Star-Testing-A.../dp/0943396905
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