Direct Positive Paper and paper monobaths?

Discussion in 'Film and Processing' started by 10986431, Jan 23, 2021.

  1. I am absolutely loving the direct poitive paper from ilford, it is great fun. I was wondering if anyone knew of any other positive paper that might have ahigher iso or whether theres a way to maybe create something similar which has a higher iso.

    Also wanted to know this. Is there a way to use a monobath with paper? I know they exist for film negatives but was interetsed to know if there was a monobath for paper. Also whats the difference between developing negatives and paper is one stronger in development than the other?
     
  2. AJG

    AJG

    Paper developers are generally more concentrated since grain isn't a concern, but faster working times are highly desirable. I'm not aware of any monobaths for paper since people generally process paper in a darkroom and the higher quality of separate chemical baths is worth the extra effort.
     
  3. You most likely desire a negative with lots of half tones, not utilizing full black or white. Benefits: you can err on the exposure side and fix that in the darkroom after capturing a moment for sure. Negative development time can be long. I did up to 45 minutes or 22 regular, with diluted Microphen. Waiting that long for every test stripe would suck.
    If you want film to contact copy offset plates from, you should choose entirely different chemicals to get clear, thick black & nothing in between.
     
  4. There used to be coin operated photo booths that take about four shots, and then some minutes later, prints come out of a slot.

    As well as I know, they use a reversal paper, as devloping, drying, and printing negatives inside the box would be a lot more work.

    I don't know where you would find the paper, or the chemistry, though.
     
  5. Direct positive material utilises the 'solarisation' effect, where the material is pre-fogged to the point that further exposure reduces the developed density.

    This results in a naturally contrasty image, and a strong dependence on the developer to get fog-free and clean whites.

    The first application of such materials was for quick duplication of lithographic (pure black & white) originals in early photocopiers.

    Basically, it's a quick'n'dirty convenience that can never give well-separated middle tones without compromising the clarity of white areas or the density of its black areas.
     
  6. It seems that there is a film like that for making copies of medical X-ray images.

    Doctors only know how to read negatives, and only have processors for them, so a film that
    will generate positives when exposed and developed in the usual way was designed.
    I believe it is something like ISO 1, though. I even looked up the patent for it once.

    Kodak, at least, uses "direct positive" also for the usual develop, bleach, redevelop positive
    imaging film. I have a "Kodak Direct Positive Film Developing Outfit", used for making slides
    from Panatomic-X. (There is a more recent one for TMax 100, which I don't have.)
     

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