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Old 29-12-2009, 09:25 AM
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Waxing_Gibbous (Peter)
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Quote:
Originally Posted by Wavytone View Post
Because these things aren't compact - they consume a fair chunk of focal length. The other reason is that some - and the unihex is an example - use a prism instead of a mirror - the prism adds spherical aberration. In a slow f/15 refractor this didn't matter but in an f/7 or faster scope it's intolerable.
Ah!
The two I've been looking at, Tak & Tec, use a mirror. It would be going in an f6.2 scope. Ok? Not?
Peter
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