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Photo Forum / Film Photography / Darkroom / January 2006development by inspection
Recently read of development by inspection with reference to infrared monocular. Have never tried this — any of you have experience to pass along on this subject? Cheers, Mike "Development by inspection" was a technique used years ago (at age 72, I can remember it--not well, but gimme a break) to develop orthochromatic film. Those films were NOT sensitive to red light, so you could watch (or "inspect") the stage of development, under a red safelight, as it progressed. One of the "ortho" films I recall using was Kodak Verichrome, but the "inspection" process was pretty sketchy, since the red safelights in the darkroom were really quite dim. The ortho films faded from general popularity as "Kodak Super XX" came to be the favorite, and then an astonishly fast film, Kodak Tri-X. These were panchromatic films, and were sensitive to the entire visible light spectrum. They had to be developed in total darkness, which put the "inspectors" out of business. After that it was time-and-temperature that you had to use to control development. And yes, I'm still shooting Tri-X. Cheers, Dick B. > Recently read of development by inspection with reference to infrared > monocular. [quoted text clipped - 4 lines] > Cheers, > Mike > "Development by inspection" was a technique used years ago (at age 72, I can > remember it--not well, but gimme a break) to develop orthochromatic film. [quoted text clipped - 23 lines] >>Cheers, >>Mike That's been my film of choice since the early sixties when I could get it in 6x9 format packs. Then I was a rank beginner, but some pictures actually came out. I remember the smell of a freshly opened pack — magic! Developed in HC110 or pyro. I tried it recently. Only feasible for sheet film. Typically a very dim dark-green light is turned on after about half of the development time. The reason green is chosen is because that is what the eye is most sensitive too-- not the film. You can then tell whether or not the highlights have been developed enough. I don't think I will use it regularly unless faced with developing film under wierd, untested lighting conditions. I noticed absolutely no fogging even though the sheets of film were exposed to the green light for up to 60 seconds. > Recently read of development by inspection with reference to infrared > monocular. [quoted text clipped - 4 lines] > Cheers, > Mike > Only feasible for sheet film. Typically a very dim dark-green light is > turned on after about half of the development time. The reason green is > chosen is because that is what the eye is most sensitive too-- not the > film. You can then tell whether or not the highlights have been developed > enough. There are several desensitizers that allow a brighter inspection light/ less chance of fogging. http://www.google.com/search?as_q=development+by+inspection+desensitizer&num=100 &hl=en&btnG=Google+Search pulls up a reasonable amount of info. -- Nicholas O. Lindan, Cleveland, Ohio Consulting Engineer: Electronics; Informatics; Photonics. To reply, remove spaces: n o lindan at ix . netcom . com Fstop timer - http://www.nolindan.com/da/fstop/index.htm > I tried it recently. > [quoted text clipped - 26 lines] >> Cheers, >> Mike One reason for waiting until about half the development time is that the film is desensitized as it develops, another reason is that it gives the developer a chance to decolorize the anti-halation backing, which, if its in place, makes inspection impossible. Development by inspection works where one has little idea of the correct development time for the film and developer combination but it takes some experience to judge the density of the unfixed negatives under the very weak light required for panchromatic films. Like many others of a certain age, my first experience in developing was of orthochromatic film under a red safelight. That's an experience I think every darkroom worker should have, but there is little orthochromatic these days. Even then I went by the recommended time rather than the appearance of the negatives.  Signature--- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com Time and temperature is best with modern panchromatic films. > Recently read of development by inspection with reference to infrared > monocular. [quoted text clipped - 4 lines] > Cheers, > Mike DBI (Development By Inspection) works best with sheet film in trays, using a pyro developer and a dark green safelight. The larger the format, the more forgiving of overexposure, so there is considerabe latitude in developing sheet film. Unlike time/temp development, I've never had a development failure with DBI, and it's not a difficult technique to learn. That being said, I rarely use DBI, preferring processing by time/temp in tubes, drums, or tanks. I have not tried the IR goggles/monocular, but if I was commited to DBI, I might. Good luck. Jay |
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