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[ATM] CDK
I also am interested in making a corrected
Dall-Kirkham scope. It seems doable for an amateur
with modest skills like me since the prolate elipsoid
can be null tested using a light source at one focus
and knife edge at the other of the elipse, and the
secondary can be tested with a spherical concave
"proof" plate of same R of C (getting same R of C will
be a challenge - any comments?). The concave spherical
proof plate can be easily null tested. I have read
these CDK can be made down to f/4 or so. I wonder if
someone would run a ray trace in Oslo for a 22"
primary, and overall optics of f/5 to f/6. What are
the tradeoffs for lower f#?
Tom W.
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