From: "Richard F.L.R. Snashall" 
To:  atm{at}shore.net
Reply-To: "Richard F.L.R. Snashall" 




mommoteandcoyote wrote:
 > Guy's n Gals,
 >
 > I have asked a few of the guys, on the side, this question...Well, now
 > I'm putting it before the board. (Gulp), Here goes...
 >
 > I have been building small Schmidt systems for many years now,
 > configured as prime focus cameras, visual Newtonians, and  photo/visual
 > Cassegrains.   Primarily, I've been using Everhart's variation of
 > "Grandpa" Bernard's vacuum pan method for producing the corrector
 > plates, with very good results.  His math was, and still is, quite easy
 > for me to understand and relate to the actual physical, quantifiable,
 > and mechanical functions necessary to produce the desired optical effect
 > upon the system as a whole.   However, in all the years of walkin'
 > around the bench and holding my eye precariously close to a very sharp
 > object, peering earnestly, hour upon hour, past a little spot of light,
 > I have never been able to grasp the basics of the polynomial equations
 > necessary to describe the specific profile on a specific corrector plate
 > and how it actually relates to the plate.  You know, the old

As long as we are asking questions about Schmidts...

I have wondered for some time "Why the Schmidt always had a flat
corrector plate?".  If it could be curved, the backside could then be
used as a Cassegrain secondary, similar to that used in the Gregory
Maksutov.

I have added something like what I am asking at:

        http://users.rcn.com/rflrs/newsch1-04x.len

I'm not saying it's good, but I think it at least gives an idea what I'm
talking about.

                Rick S.

 >
 > Talk with you soon,
 > Coyot‚

--- BBBS/NT v4.00 MP