Celestron 8 inch Schmidt Camera

I will soon have in my possession a Celestron 8 inch Schmidt Camera. :-)
The f.o.v. is rather limited using the standard 35 mm film holders on the 8
inch Schmidt camera. Has anyone tried making a larger format film holder?
The University of Victoria has an old 10 inch Schmidt Cassegrain that can be
converted into a Schmidt camera by adding an extended tube assembly
containing a new corrector and film holder. It uses a round film format,
the film being cut out with a cookie cutter device. This should be possible
with the 8 inch I would think, thus increasing the f.o.v.
Anyone know where I can find some 120 or 4X5 Tech Pan film so round disks of
film could be cut from it? If you have made such a film holder I would be
interested in hearing the details! Making such a large format film holder
would be an interesting project for the future.
Ed

I'm sure someone has, but then there are the questions of (1) where are you
going to get larger film stock that doesn't cost an arm and a leg, especially in
this world that's converting to CCD/CMOS at an ever accelerating rate, and (2)
wouldn't that affect the effective aperture, dimming the view and introducing
diffraction artifacts, if nothing more?

--- Dave
--
----------------------------------------------------------------------
Pinprick holes in a colorless sky
Let inspired figures of light pass by
The Mighty Light of ten thousand suns
Challenges infinity, and is soon gone




"Ed Majden" wrote in message
...
I will soon have in my possession a Celestron 8 inch Schmidt Camera. :-)
The f.o.v. is rather limited using the standard 35 mm film holders on the 8
inch Schmidt camera. Has anyone tried making a larger format film holder?
The University of Victoria has an old 10 inch Schmidt Cassegrain that can be
converted into a Schmidt camera by adding an extended tube assembly
containing a new corrector and film holder. It uses a round film format,
the film being cut out with a cookie cutter device. This should be possible
with the 8 inch I would think, thus increasing the f.o.v.
Anyone know where I can find some 120 or 4X5 Tech Pan film so round disks of
film could be cut from it? If you have made such a film holder I would be
interested in hearing the details! Making such a large format film holder
would be an interesting project for the future.
Ed

in article bWQEe.2644$vY2.2134@trnddc09, David Nakamoto at
wrote on 7/24/05 11:16:

I'm sure someone has, but then there are the questions of (1) where are you
going to get larger film stock that doesn't cost an arm and a leg, especially
in
this world that's converting to CCD/CMOS at an ever accelerating rate, and (2)
wouldn't that affect the effective aperture, dimming the view and introducing
diffraction artifacts, if nothing more?

--- Dave

I'm interested in meteor work so a larger f.o.v. is highly desirable.
You should be able to get 4 - 2 inch diameter disks out of a 4X5 sheet film.
There is also a fellow that sells Aero Plus X extended red, roll film 9-1/2
inched wide in a 125 foot roll for around $80.00 USD. I don't think I will
live long enough to go through a roll of that with the Schmidt. The late
Peter M. Millman and Fred Whipple used a large Super Schmidt camera designed
by James G. Baker for meteor height and ablation studies back in the 1950's.
Such systems are useful for wide field Comet photography also. When I can
get a large format 2-1/4 inch or larger CCD camera for less than the price
of a new car I may consider the switch!
Ed

http://members.shaw.ca/epmajdem/index.htm

Ed Majden wrote:

Anyone know where I can find some 120 or 4X5 Tech
Pan film so round disks of film could be cut from it?

Last time I checked B&H still had some 4x5 Technical Pan
available. I bought a couple of boxes of it from them
myself, but use it for terrestrial photography.

Laura Halliday VE7LDH "Que les nuages soient notre
Grid: CN89mg pied a terre..."
ICBM: 49 16.05 N 122 56.92 W - Hospital/Shafte

"laura halliday" wrote:

Anyone know where I can find some 120 or 4X5 Tech
Pan film so round disks of film could be cut from it?

Last time I checked B&H still had some 4x5 Technical Pan
available. I bought a couple of boxes of it from them
myself, but use it for terrestrial photography.



A few months back a friend of mine checked with most of the camera stores
and bought up all of the remaining 35mm Tech Pan bulk rolls that he could
find. I think he now has the world's largest supply of 35mm Tech Pan. I
don't know about larger format.

George Normandin

"Ed Majden" wrote
...
I will soon have in my possession a Celestron 8 inch Schmidt Camera.
:-)
The f.o.v. is rather limited using the standard 35 mm film holders on the
8
inch Schmidt camera. Has anyone tried making a larger format film holder?

Ed,

A while back I read an article by David Levy (of Shoemaker-Levy 9 fame)
discussing his two Celestron Schmidts that he had converted to medium format
film. He mentioned that it took over a year to get just one of them focused!

I also have heard of two guys in Germany who have modified Celestron
Schmidt cameras to take CCD chips. I'm not quite sure how they did it. The
chip would have to bend. Of course they now use CCD with the Palomar 48-in
Schmidt.

Each Celestron Schmidt has filmholders that only work with that
individual camera. The astro club I belong to has a 8-in that I've used over
the years (not much lately) and it has kept focus since the late 1980's when
it was new. I own a 5.5-inch camera that is a real antique. It was made by
"The Celestron Pacific Company" and is SN #33. It was re-manufactured by the
company (? I forget the name) that did that for a number of years, adding
new focus hardware. They no longer do this work. This camera is in perfect
shape. From this point forward I expect to use Kodak 100asa color slide film
with these cameras. You really need dark skies to use them.

George Normandin