Re: ATM Re: Corrector plates

["mommoteandcoyote" <mommoteandcoyote@msn.com>]

Frank,and Fellas,

>From the coma stand point, the Gregorian makes sense.... but is there a way
to make the Cassegrain system work without folding "Donuts" on all the
surfaces

Coyoté


----- Original Message -----
From: "Frank Q" <frank@katestone.com.au>
To: "Richard F.L.R. Snashall" <rflrs@rcn.com>; <atm@shore.net>
Sent: Wednesday, January 22, 2003 8:40 PM
Subject: ATM Re: Corrector plates


>
> Hi Richard/All,
>
> This is an interesting idea.
>
> The plate would take the shape of a meniscus lens (sort of) or
> perhaps a mak corrector (again - sort of) with the 4th order
> schmidt polynomial figured on a surface.
>
> If we make it bulge towards the mirror, we can make the surface
> spherical (D-K); hyperbolic (CASS) or if we turn it around (bulge
> away from mirror) we could make it elliptical like a gregorian...
>
> The possibilities are interesting and numerous !!
>
> By the way, has a gregorian with a spherical concave secondary
> (all corretion relegated to the primary) ever been designed/built????
>
> Cheers
> Frank Q
>
> ----- Original Message -----
> From: "Richard F.L.R. Snashall" <rflrs@rcn.com>
> To: <atm@shore.net>
> Sent: Thursday, January 23, 2003 12:12 PM
> Subject: Re: ATM An Old TMs Simple Query
>
>
> >
> > 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,
> >  > Coyoté
> >
> >
> >
>
>
>