Re: Grinding a flat

Jan R. Sugalski (afn19866@freenet.ufl.edu)
Tue, 2 May 1995 01:17:09 -0400 (EDT)

In my opinion, if you do not have access to a master flat, you should use the three alternating disk method and read the interference patterns. There is a description of this in Allyn J. Thompson's book MAKING YOUR OWN TELESCOPE. I have used it successfully to make many flats. You can use a mercury vapor lamp or even a flourescent lamp will do to read the patterns. It is worth the effort since you will learn an enormous amount about figuring. You can Email me for more information about all this if you decide to do it. Jan

Pushing glass will set you free!

On Mon, 1 May 1995, SCN User wrote:

> Date: Mon, 1 May 1995 17:30:58 -0700
> From: SCN User <notpete@scn.org>
> To: atm@best.com
> Subject: Re: Grinding a flat
>
> >
> >Sigh, a friend and I occasionally discuss making a flat, but we are
> >intimidated by obtaining a reference. Is there a way to test a flat that
> >is as easy to use as a ronchi test? If we could, we would like to make a
> >6-inch flat for a celeostat (spelling?). Well it is just a thought - any
> >ideas?
> >
> >Bob
> >
> >):-{])) <---- madden@netcom.com
> > madden@svpal.org
> > Remember amateur astronomers:
> >"keep looking for the next Universe"
> >
> >
> >
> There was a Gleanings article by Ed Jones a few years ago about testing
> flats using water as the reference. I tried it and got it to work, but
> you would need to have lots of patience to figure a flat using it. The
> set up and adjustment can take a whole bunch of time.
>
> Peter
>
>
>
> --
> Peter Hirtle notpete@scn.org Seattle, WA.
>
>
>
>