Re: ATM Corrected Cassegrainian

[Aplanatic@aol.com]

Dominic,

Do you have any idea how difficult it is to accurately make a 32" Schmidt corrector for an f/1.8 system?  Yikes!  :-)
 
I've made a few correctors in the 9-12 inch size.  A good 30" f/1.8 corrector is simply not possible (for the amateur in a finite amount of time).  Sorry.

Dave Rowe

Dominic wrote:

> > I could propose another alternative... First, get that
> > sphere down to F/1.8 or so. This is about the height for
> > average European male (guessing from Guy's last name),
> > namely 183 mm. A typical Schmidt corrector diameter for
> > this 40" mirror would be around 32", perhaps a little 
> less.
> > Optiwhite plate glass could be used. Correctors of this
> > type are placed at ROC, so the system ends up twice the
> > height of a human. I think this ends up being easier than
> > some of the folded systems that would preserve most of
> > the length of the present system.
> > 
> > Dominic