Re: [APML] Another intro

["Steve Walters" <swalters@att.net>]

In addition, the lower magnification secondary reduces the image shift due
to thermal expansion.

Steve...

swalters@att.net
http://astrophoto.home.att.net

----- Original Message -----
From: Gene Horr <genehorr@texas.net>
To: <astro-photo@seds.org>
Sent: Wednesday, August 22, 2001 3:05 PM
Subject: Re: [APML] Another intro


> Jon Kolb wrote:
> >
> > Tom,
> >
> > > Has anyone heard this rumor about the C 9.25 also?  (I don't
> > > have any hard
> > > facts to back this up.)
> >
> > I recall reading somewhere that the C9.25 has an f/3.3 primary and the
> > secondary magnification is about 3, whereas the "normal" SCTs have an
f/2
> > primary and a secondary magnification of 5.  I may have the specific
numbers
> > wrong, but the C9.25 supposedly has a slower primary.  That could be the
> > reason for the flatter field.
>
> That's it.  The numbers may be off a little, but you're in the
> ballpark.
>
> Gene Horr
> genehorr@texas.net
>
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