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Old 13-09-2018, 04:29 PM
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Jason D (Jason)
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Join Date: Aug 2009
Location: California USA
Posts: 117
Quote:
Originally Posted by bojan View Post
It may also be a bit of wrong secondary offset...
Because the light beam reflected from primary is conical, for it to pass the secondary unaffected by vignetting, it needs to be positioned a bit away from focuser (2~4mm, depending on f/ ratio and other factors).
Do you still believe that an away-from-focuser secondary mirror offset is needed to avoid vignetting? That is what I understood from your above statement.

Jason
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