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Old 13-09-2009, 06:57 PM
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Peter Ward
Galaxy hitchhiking guide

Peter Ward is offline
 
Join Date: Dec 2007
Location: The Shire
Posts: 7,136
Quote:
Originally Posted by Grahame View Post
Gday Peter,

There was no focal reducer in use when the first image was taken. The second image was using a taka Field Flattener.

Grahame.
Graheme..I have to say this looks odd. Have you adjusted the collimation at all? (I'm wondering whether the secondary is being stressed somehow...fix: loosen all three adjustment screws and gently re-collimate)

I'd also play with the focus. RC's have curved focal planes...often mistaken for coma. I always use stars about 2/3rd's out from the center.

rgds
Peter
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