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Old 22-11-2013, 01:53 PM
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Shiraz (Ray)
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Shiraz is offline
Join Date: Apr 2010
Location: ardrossan south australia
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Originally Posted by RickS View Post
That's not a corrected Newt...
or a corrected SCT.... and the quoted data shows how good a couple of the scopes are if you ignore the curved focal plane!!. This is a fine example of why spot diagrams are such a dangerous indicator of performance - they are too easy to mis-read.

If you really want to see how good Newts and SCTs are Allan, have a look at what the planetary imagers do - Newts and SCTs are the main two types of scope used and both can get down to the diffraction limit in good seeing. For DSO imaging though, the atmosphere is so messy that it really doesn't matter how good the scope is (within reason) - the atmosphere will determine what you get, not the scope. Arguing over spot sizes completely misses the elephant in the room - the seeing.

Last edited by Shiraz; 22-11-2013 at 02:22 PM.
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