Re: ATM Building a Cassegarian

[Bratislav Curcic <epabcc@epa.ericsson.se>]

> A properly designed and constructed Cassegrain will, IMHO, outperform
> a Newt. on lunar, planetary and stellar observations.

Rik,
can you elaborate why ? Apart from large image scale, I can't see any
advantage to a Cassegarin, and there are many disadvantages : difficulty
in making (fast primary far more difficult that run of the mill f/6 used
in planetary newtonian, secondary even more difficult, while perfect flats
are turned out by thousands), obstruction is higher, difficult to properly 
baffle without increasing obstruction even higher, another reflection
needed (if you care about your neck) ... It is understandable that once
you go to a meter class telescope you HAVE to go Cassegrain way, but that
is pure economy. I'm quite sure that given amount of time any optician
will make far better medium parabola than fast parabola (or ellipse) and
a matching covex hyperbola (or even sphere). What is that I'm missing here ?

Bratislav