Questions/Comments on Primer - Telescope Types

[Adrius]

you forgot the last in line and the most expensive! "Ritchey-Cretien Reflector" allmost all of the worlds obserbitorys use Ritchey-Cretien Reflector Design's Including the Hubble Space Telescope.

[Astroman]

A Ritchey-Cretien is a type of Cassegrain design that is most effective in larger formats above ~14".  Most amateurs will never own one.  It uses a parabolic primary and a hyperbolic secondary to eliminate the corrector plate of the Schmidt Cassegrain.  If you include it, you need to include a Loury-Houghton, a Schiefspiegler, Zolo and others.   I think the purpose of this subject is to introduce newcomers to very basic types one might find in an astronomy shop or for sale online, not identify all types of scopes.

[FLO]

you forgot the last in line and the most expensive! "Ritchey-Cretien Reflector"...

Astroman is right Adrius (he usually is ... dammit ). 

Nevertheless, it was worth mentioning as there are at least twelve dealers in the UK where telescopes based on the Ritchey-Cretien design can be purchased by mere mortals such as ourselves ... well, perhaps not me; my pockets aren't deep enough!!

Steve

[Adrius]

true that, strange enouth though you find em like cakes in aust, but yeah they are very expensive as well.

[themos]

There exists an interactive geometry package called Cabri and a Java implementation of it, Cabrijava. One can find some "gadgets" that allow you to explore geometrical optics and the design of telescopes. Have a look at this, for instance:

http://www.sciences.univ-nantes.fr/physique/perso/cortial/bibliohtml/cabrijava-optgeo.html

Beware, it's all in French!