Re: [ATM] Scmidt Camera (Celestron) Question

[George Anderson <georgea@cam.org>]

The 5.5 inch Epoch-Celestron schmidt camera does have some issues with
vignetting. There is very little difference visually between the 5.5 and
the 8 inch versions other than size, so any photographs for the 8 inch
will supply information.
Have a look at Robert Reeves website on his write up on rebuilding the 8
inch schmidt.
http://www.robertreeves.com
The film holders for the 5.5 have a different curvature from those used
in the 8 inch (IIRC).
For your 200mm you will need to calculate if the ROC of your primary is
the same as the ROC of the 5.5. If it is then you should be able to use
the film holders. I believe that the 5.5 inch was an f/1.8 instrument.
One catch... There are two different film holders for the cameras. One
is for straight photography and the other is for filtered using Kodak
Wratten filters. The difference is small but will affect the focus. I
believe that Robert's website gives the details as to how to spot the
difference between the two film holders. Also you may want to
build/modify your film holder to allow roll film rather than cutting
film chips. Again Robert's website has details on this.

George Anderson
Montreal Canada

Clear skies and good health

dezrteagle wrote:
> 
> Pleasant pickle here. Had a brother win a storage auction recently, and knowing my interests, e-mailed me a pic and some info of a part of it's contents. Turns out to be an old Celestron 5.5" Schmidt. The corrector is cracked, the primary chipped and the tube is in bad shape, but there appears to be 3 intact film holders. I am currently constructing my own 200mm camera (thanks for the tips!), and would like to use these, unfortunately my bros' job took him out of the country for the next 3 months, so I won't see them for some time. I should be finished by then. I have never owned one of these Celestron instruments and can't gather enough info on the web to ascertain whether I can incorporate these in my camera (without having to modify and re-focus the instrument down the road). I'm machining my own film holders and will be using magnetic retention to hold them in place. Anybody out there that can supply me with mechanical dimension details (maybe a pic or two) of the celestron film
> holders? Just trying to avoid additional work in the not too distant future. Thanx!
> 
> P.S.-is it my imagination, or are the Celestron correctors the same size as the primary? Any vignetting comments?
> 
> dezrteagle@cox.net
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
_______________________________________________
ATM mailing list http://www.atmlist.net/