Re: [ATM] Schmit corrector grinding

[tillerman1@videotron.ca]

Hi
I am using multiple sources for this. A combination of R&V, along with the schmidt corrector grinding info provided by Bob Pfaff about 10 years ago on this list (somewhere I have a hardcopy of a website where it was presented, as well a a softcopy on some CD somewhere), and I used Dave Rowe's vacuum pan xcel spreadsheet. Version 1 where a sphereometer is used as opposed to a vacuum gauge.
And the corrector designed and tweaked using Oslo.
The camera uses(will use) a 6" f/2 mirror from surplus shed, and the unobstructed portion of the corrector is 5.75", more than the ideal but I can work with the vignetting and light falloff at the edges.

George Anderson
Montreal Canada

Clear skies and good health

----- Original Message -----
From: Dominic-Luc Webb <dlwebb@canit.se>
Date: Tuesday, February 13, 2007 1:18 pm
Subject: Re: [ATM] Schmit corrector grinding
To: tillerman1@videotron.ca
Cc: ATM Superheros <atm@atmlist.net>

> 
> I would be interested in your sources of info on this topic,
> if this is possible. I enjoy reading on this subject and
> once in a while find people have used sources I was not
> aware of.
> 
> 500 grit sound close to what I use. The curve on these
> correctors is usually very small. Consider one of my
> Schmidt designs using rather strong curve (primary is
> 310 mm F/1.55):
> 
> http://www.canit.se/~dlwebb/catadioptric/310schmidt/schcorr.jpg
> 
> You will notice the deepest point in the corrector is only 80
> microns less than the highest point (axis). Design uses 6 mm
> glass, which is readily available where I am and design can
> tolerate a little less thickness. I went for 600 grit assuming
> this would get me my curve quickly without removing excessive
> glass.
> 
> Is the other side of your corrector flat or are you splitting
> the curve between the two sides?
> 
> Dominic-Luc Webb
> 
> 
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