Re: ATMing in the September Sky & Telescope

[Daniel Fundo <fundo@bellsouth.net>]

<< Clyde's scope is in fact a Mersenne reflector, a design that doesn't
get a lot of play amongst ATMs.  Given the number of interesting
features this scope has, that is something of a surprise.  Perhaps after
some of you have seen Clyde's piece in the September Sky & Telescope
this will change.  >>

Gary,  I have heard of the Mersenne design before, but I thought it was
an afocal Cassegrain arrangement.  This should be interesting.  With the
availability of ray tracing software, the imaging lens could be designed
with the necessary corrections to make it work with current advanced
eyepieces.  Is this what Clyde has done?  It seems to me that you could
also cut your secondary obstruction to 10-15% of the primary diameter.

A member of the Amateur Astronomer's Association of Pittsburgh was
working on an f/4 16 inch Mersenne on a Beavertail Springfield mounting 
when the AAAP had an advanced optics workshop in the Allegheny
Observatory in the early 1960's.  He got the idea from an S&T article
and the telescope that George and Tony Doschek built (S&T July 1961
Gleanings for ATMs) on a beavertail mount.  (A 16 inch was a very big
deal at that time!!!!)  The only problem with the Doschek's telescope
was that it was an f/19!

I'm looking foward to this one!  Thanks for the heads-up.
*****-----
Dan F.
Secretary/MAS
Memphis, TN