Rick, Is it even worth trying to use an orange or red filter to try to correcr some of the blue sensitivity?
Gene Rick Dingus wrote: > > Many years ago I built a 16" X 20 " field camera and experimented with using > 16 " X 20" generic ortho film from Freestyle instead of regular panchromatic > film because it was cheap and because it looked a lot like 19th Century film > when processed for continuous tone. (Blues are rendered lighter in tone, > reds dark, and it is so slow that you end up with time exposures even in > bright sunlight.) The film manufacturers all refused to advise me, saying > that high contrast film was not intended for continuous tone and they > wouldn't guarantee the results. But by trial and error, and months of > experimentation, I found a method that worked well. > > Testing the development and exposure by printing and not by eyeballing is > essential because the drastic dilution changes the color of the film to a > muddy brown--what looks to the eye like a very flat negative actually prints > on photo paper with much more contrast because of the change in color, which > is similar to the color of a safelight. The film speed is also extremely > slow, about ISO 1.5 instead of 6, because you need shadow detail if you're > trying to avoid high contrast. > > Even development was another problem with such large negatives. I settled > on using a Dev-Tec color print processing tube with constant rolling > agitation, reversing direction every 30 sec. Keep in mind "expose for the > shadows, develop for the highlights" and print on photo paper to evaluate > exposure and contrast (minimum exposure time for maximum black of the clear > edges of the film). Increased development increases contrast, decreased > development softens contrast. Development is affected by: > 1. Time (the longer the time the more the development) > 2. Dilution (the stronger the concentration the faster the development) > 3. Agitation (the more agitation the faster the development) > 4. Temperature (the warmer the developer, the faster the development) > > I ended up with something like 1/4 oz HC110 concentrate (straight from the > original bottle, not diluted into stock solution like Kodak recommends, in > 32 to 40 oz water at 70 degrees F for a development time of about 5 1/2 to 6 > 1/2 minutes. My students have achieved similar results using 35mm Kodalith > film, resulting in 35mm negatives that are so fine grain that they almost > appear to be large format. > > Try to keep your development time to 5 minutes or longer for even > development. Bracket your exposures and development to find the best kind > of detail and contrast. Its slow and unconventional, but it does work and > can create a beautifully delicate tonal range that takes full advantage of > all the blacks, whites and middle tones afforded by your paper if tested and > handled carefully. > > Good luck. > > Best, > > Rick Dingus > > > From: Gene Johnson <[EMAIL PROTECTED]> > > Organization: @Home Network > > Reply-To: [EMAIL PROTECTED] > > Date: Mon, 15 Oct 2001 11:00:57 -0700 > > To: cameramakers <[EMAIL PROTECTED]> > > Subject: [Cameramakers] industrial films > > > > Hello Cameramakers, > > > > I was wondering if anyone has had experience with using any of the Kodak > > or other large industrial films like precision line film or reproducing > > film in their large format cameras. I see this stuff as surplus from > > time to time, and was curious about it. I know these are generally > > ortho films, and I have no experience with that. Will I be able to > > develop it with ordinary developers? Also, I just bought a huge roll of > > Aerial reproducing film, Kodak SO-192 for just about nothing. It's 5" > > rollfilm and I've also just bought a 5" rollfilm back to use it with. > > Since there are no available tanks to develop it in, I'm hoping I can > > modify a multi-roll Jobo tank to allow me to develop 6 feet or so at a > > time. I also hope I can "reverse engineer" the back to see how hard it > > would be to make approximate copies. > > > > > > Gene Johnson > > _______________________________________________ > > Cameramakers mailing list > > [EMAIL PROTECTED] > > http://rmp.opusis.com/mailman/listinfo/cameramakers > > _______________________________________________ > Cameramakers mailing list > [EMAIL PROTECTED] > http://rmp.opusis.com/mailman/listinfo/cameramakers _______________________________________________ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
