From Camera Obscurer to Digital copying

[linhofbiker]

I made a Camera Obscurer for my wife's art class. I used a telescope objective of about 30 inches focal length, a front silvered large piece of mirror to shoot the real image up onto a piece of glass with waxed paper laid on top. It focused by sliding the front of the box. The image obtained was quite remarkable and about 10 inches square. I built it several years ago and still have it in the attic of my little workshop. It is cumbersome to use but does the job. Apparently this is what some old masters used to get the realistic perspective in their paintings.

My 5x7 is awaiting new bellows. I would like to photograph the ground glass with my Sony A850. Don't know how to do this exactly - should I replace the ground glass with clear glass and put some wax paper on it like the C.O.? I do have a Satin SnowTM screen as well as the standard screen supplied by Linhof. It has been suggested that the BossTM screen would be good since it has a wax layer.

[jnantz]

i've photographed off of the waxed paper before .. if you are good with photoshop
you can make it seem ok but there can sometimes be "hot spots" ...

can you take the glass on and off easily ? if you can, and you have some tape ...
you can make "retina prints" as i learned from Joseph Nicéphore Niépce
well, he used paper he coated with silver nitrate but you can use regular
olde, store bought photo paper ( or even photographic film ) ...
after the image is focused on your "screen" cover the lens, and pop the
photo paper on the screen so the emulsion faces the lens and records the image.
be advised, it is not a quick process, and it may take anywhere from 20 mins
to 48 hours depending on the type of light and your subject ... ( and lens speed )
think solargraph but with a camera ...
and to squelch your fears, no the photo paper and film doesn't turn black instantly it is exposed to light
you have plenty of time to do the taping and if you search on photrio.com in the articles section
under NedL you will find an article on "fixing a solargraph" which will help you fix your image ...
otherwise the paper turns white in fixer and black in developer ( just like Joseph Nicéphore Niépce's images )
you wont' have Louis-Jacques-Mandé Daguerre to team up with, hold you by an ankle shake the $$ out of your pocket and then
take you to the cleaners but ... if you have mr epson or similar electrification device you can use that to use mr gymp or mr fhoto shoppe
or if you have one of those devices made by or inspired by Chester Carlson's you can get an archival xeroxagraphical
facsimile negative made with carbon toner and heat to work on with delight.

have fun, the trail was bushwacked nearly 200 years ago it seems overgrown but after a few steps its an easy path ...