The site covers the design and calibration of Schmidt
Cassegrain telescopes and focal reducers, with examples of CB245
ccd and photographic imagery. It also has a free eyepiece field
of view (FOV) timer software package for PCs.
Schmidt Cassegrain owners can discover how to measure and
compute the focal ratio changes of their telescope from
adjustments to the focus control, with my report.
The focal ratio of my C11 telescope changes from F/9.1 to
F/16 over the full focus travel. It is this large change
that allows one to use many focal reducers, ccd
and photo accessories on these telescopes
Robert Deane
Updated September 2003
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