> John Gregory, for the tyros information, is the person who designed the
> Gregory-Maksutov during the 50's. Albert Ingalls popularized the design in
> the pages of Scientific American and the Maksutov Club built a number of
> these telescopes. That's the design the Questar, C-90, Intes et.al are
> based upon. Bulletin C is the classic paper describing it in detail,
> giving the curves and such.
Although Gregory was first to publicly give all the details of a Maksutov-Cassegrain using back of a menisk as a secondary, it really was Dimitri Maksutov himself who has "designed" a Mak-Cass (shown even as early as '47 (?) in his infamous JOSA paper), together with "true" Maksutov and Maksutov-Gregorian. He and his Russian (sorry, Soviet) colleagues had made working prototypes of Mak-Cass and Mak-Gregorian in early forties, but design details were never published (at least to my knowledge). I'm not nit-picking, just want credits where they are due to.
BTW, as far as I know, both Questar and Intes use separate radius for a secondary (either separate mirror, or ground-out central part of a corrector), so strictly speaking, they are not based on Gregory's design.
Bratislav
PS I don't want to be misunderstood, I _am_ great admirer of John Gregory, but some things simply have to be clarified. I am sure that he would even do this himself, if he had a chance