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Re: Design Review

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Posted by Walter Hamler on February 22, 2001 00:42:35 UTC

I ran the numbers on my copy of newt and basically you need a 1.52 at a minimum as well as a 2" focuser to get the light cone to the eyepiece without vignetting. Actually a 1.83" may be better. Don't let those contrast degradation warnings get to you. I recently upped the size of my diagonal in a 10" f/6.8 to allow a larger fully illuminated field and saw no difference in planetary performance, yet the wider field views were in fact noticably improved. There was a very good article concerning this subject in a S&T issue a few months back, maybe even 6 months. Check it out.

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