Re: ATM The Glass Giant

[Anthony Stillman <atmer@flash.net>]

>Well, the "perfect machine" was less perfect than it could have been if it
>had used Ritchey-Chretien optics.


This would not have worked.  The 200 inch Palomar is a three way
convertable.  It is used as a prime focus instrument, and with the addition
of one of two different secondaries, as a true Cassegrain or a
Coude-Cassegrain.  A hyperboloidal primary could not have fulfilled these
design goals.  Further, the aplanatic Cassegrain isn't really much of an
improvement.  In exchange for severe off-axis stig, strong field curvature,
a degraded spot diagram, and a sizable increase in the difficulty of
fabrication, you get, round stars.

Anthnoy