Re: Re:ATM Cassegrain as second telescope project.

["Ken Hunter" <kb7h@onemain.com>]

It would have a useful correction if you made the primary focal length
long enough that whether you correct or not is a moot point.

i.e. Make it so long that it cannot be recognized as a RC anymore.
(not practical)

Ken Hunter


----- Original Message -----
From: "Steve Beccue" <lsteve@daffodil.beccue.org>
To: <kwhitefire@juno.com>
Cc: <suzyj@bigpond.com>; <atm@shore.net>
Sent: Tuesday, August 06, 2002 10:57 PM
Subject: Re:ATM Cassegrain as second telescope project.


>
>
>
> Could you please expand on this?  I am considering a RC for a 32".
At
> what f/D is the primary separately useful?
>
>
>
>
> >
> > If you're going to do a variation on the theme of a Cass, go with
a Ritchie-Chreitien.  It
> > has no coma, and if you make it with a long enough f/D it will
have a
> > separately useful primary mirror.  Difficulty is slightly greater
than
> > with a classical Cass, but the optical system is far superior to a
DK.
>
>