Re: cassagrain doublets

Dave Schaack wrote:
"Narasimham" <mathma18@xxxxxxxxxxx> wrote in message news:1151576584.082566.259170@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
What other combinations are possible and/or available apart from the
classical paraboloid & hyperboloid combination?


A wide variety of combinations have been used; generally given their originator's names. Look up Dall-Kirkham and Ritchey-Chretien (spelling?) for starters.


Also Pressman-Carmichael. Virtually any conic section can be made to work, with varying degrees of abberation.

--
jeff
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