re: bellows chat, Aerial film contrast 1. Bellows support. Manufacturers have done it in one of two ways. a small rigid support on the bottom that is attached to the rail, and a snap connection that holds together several inches of bellows (basically the amount your lens would require for close-up that you normally don't use.) A bellows doesn't need much to support it. A little lift from the top or a little push from the bottom.
2. Other possibilities: New materials. bungicord on the top between the standards--just enough tension to lift the bellows sag without distorting the standards. 3. The Deardorf bellows folding within bellows. It's not all that tricky and its not a bag bellows. Its a bellows that has a bulge such that the smaller cross section can squeeze past the larger dimension part. This gives it a little more support. 4. Internal reflection and dryer vent. A dryer vent type material might work. I think the idea has real merit. In fact rather than try to tweak some existing materials just get some spring wire wind it into a nice diameter and then glue two pieces of black fabric inside and outside the 'spring' cylinder. An advanced design might square off the corners. 5. Internal reflection. It should be added that it's not just light tight matte black that is needed inside your camera. The folds in the bellows are part of the 'light trap.' Even black fabric will reflect enough light to fog film if it is stretched flat such that the angle of incidence from lens spill equals the angle of refraction hitting your film plane. Real world? If your bellows is always stretched straight out to the limit you risk this. 6. Lens Shade. 5x7 with a reducing back--interesting idea. With three 4x5s it's a little late for me to change now and my Horseman 8x10 is too durned heavy to be carting around on my shoulder. I've found that it is far more important to keep stray light off the lens to keep light spill from fogging the film. Get a lens shade or a bellows or at least shade your lens from the sun or light source, or the sky with the dark slide while exposing. It really does help. You might not even notice it until you shoot two sheets of film of the same subject one with a shade and one without. 7. Aerial film and contrast. Sounds like the film test with detail-less ground areas and dense skies is a problem caused by the 'solution' needed for aerial photography. One of the biggest problems in aerial photography is getting enough contrast. Kodak trys to engineer increased contrast into the film. Try low contrast developers, fogging the film (pre or post amount to the same thing). If I was playing with that film I would (1) try to establish an ISO for the shadows and then (2) find what the minimum process time is for PMK Pyro (that I use) and then (3) shoot a test & give it a minute or two over the minimal PMK time. 8. Pre and post fogging can also help your shadows and lower the contrast of your aerial film. For transparency film-the most critical test-I will keep the camera focused on the subject or re-focus it at infinity and then shoot a white card 3 1/2 to 4 stops underexposed. The card being too clase to focus provides exposure without detail. I meter with a spot meter from the camera position and then stop down. e.g. f8 at 1/60 shoot f16.5 at 1 1/125. With negative film start here and then go farther until you fog it badly. Pre/post fogging (also called 'flashing') adds density to the shadows without affecting the highlights. With color transparency film it'll add just enough exposure to the dark areas to pick up texture. Overall it also lowers contrast. 9. Pre/Post fogging and B&W negative. Usually you don't need to do this with negative film. Just fiddle with the contrast while printing. Sometimes I'll post-flash the film if I've processed some film and the shadows are weak by just a hair. Also I haven't seen a bit of difference between pre and post fogging. The literature (adults like Ctein doing tests) supports this. I would think that reciprocity sensitive films like Polaroid Type 55 would show a problem with pre or post before any other type of film. With transparency film I shoot of paintings--very critical color corrections--I can post flash days later and use these numbers as pre & post flash exposure the next time I shoot film with no change in results. As always your mileage may vary. Will ---William Nettles [EMAIL PROTECTED] Nettles Photo / Imaging Site http://www.wgn.net/~nettles _______________________________________________ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
