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  1. #61
    David A. Goldfarb's Avatar
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    Well, one nice thing about monobaths is that they are quick and easy to test.

    I tried adding 1 g/l KBr with the 105 g/l hypo that I'd settled on and got less fog, but also less shadow detail, so I tried 1 g/l KBr with 100 g/l hypo and got still less fog, but not as little as I got without the KBr (which suggests something else is going on), but also less contrast than I got without the KBr and the shadow detail looks okay. I'm thinking some of the fog may be partially a film issue, since I'm now using a different emulsion batch (just one month older) than I was using for my first three tests. At this point, I think I'm tweaking at the margins, since the tests are all pretty close to each other.

    When the film's all dry I'll post some scans.
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  2. #62
    Photo Engineer's Avatar
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    David;

    Although Grant is the expert on Monobaths, IMHO, I think his belief was that they should be designed or tailored to work with a particular film as they did with the space sattelite films of the 60s and 70s. This was the BiMat film that came in 2 parts, one being the tailored film and the other was the sheet with a sponge like layer of monobath for processing in space and relay of pictures to earth.

    In any event, due to all of these problems he had pretty much abandoned the monobath as a viable process for all films for the reason given above and had gone on to designing a product/monobath combination.

    His final result was an ID paper that was exposed and then processed by heat giving a fine image with good stability. This can be tracked in patents and reports by Grant and Bill Humphlett and myself. That is pretty much where real 'monobaths' ended up. It contained a developer and a blocked fixing agent / alkali that gave a complete, stable image in about 2 seconds.

    I never heard any further efforts on monobaths from Grant after BiMat.

    PE

  3. #63
    David A. Goldfarb's Avatar
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    Yes, in the book he states that monobaths had to be tweaked to individual films or papers, and that he felt they could produce results as good as conventional developers when used that way, but that that requirement of one formula for one film didn't make them commercially viable.

    This makes sense to me, since we wouldn't imagine a conventional developer that would have the same developing time for all films, so in a monobath the developer and the fixer would likewise have to be balanced for each film individually, with a little extra tweaking for problems like fog and sludge (sounds like winter in Rochester).
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  4. #64
    Ian Grant's Avatar
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    Ron, Crawley wrote a review on Monobaths in the 70's, he'd also done quite a bit of work on them about ten years before, and made references to Haist, unfortunately due to typos his name was misspelt at the time.

    My own practical research into monobaths somewhere around 1978/9 indicated exactly what you say "they should be designed or tailored to work with a particular film". When the balance is right the results are very good, if not excellent. It was a descendant of the "Lumiere" family who suggested I look at Monobaths

    Ian

  5. #65
    Photo Engineer's Avatar
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    You know, it is funny, but I never read "The Monobath Manual" nor did I have a copy of it. I only got a copy of "Modern Photographic Processing" recently, as I could no longer use the EK library easily. It was a case of having "the man" right here a few blocks away or working with me here in my darkroom or at EK that convinced me to not buy either. I had him to talk things over with as a friend, and also I read the "MPP" drafts over and over while helping him edit it.

    He used to come over here and we would work in my darkroom. Would you believe that Grant didn't have a home darkroom except for simple B&W film processing? In any event, I've never read the book, but have the word from him and have seen his R&D efforts. Some were quite amazing.

    PE

  6. #66
    Ian Grant's Avatar
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    From what I remember reading during my research in the 70's the Russian work with Monobaths was far more advanced, there was a lot more innovative research there, but it still hit the buffers.

    Ian

  7. #67
    David A. Goldfarb's Avatar
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    Out of curiosity, I did a Google search in Russian for "проявляюще-фиксирующий раствор" ("developing-fixing solution," which seems to be the most common term for "monobath"), and I did turn up a PDF of a general B&W processing manual, but a quick search (hey, Acrobat can search in Russian) reveals only a passim reference to monobath processing in space.
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  8. #68
    David A. Goldfarb's Avatar
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    Here's the result at 100g/l hypo and 1g/l KBr. It's very close to 105g/l hypo with no KBr. The former has a little better shadow detail, the latter has a little more contrast.

    Both are very sharp. High acutance seems to be the photographic attraction of this formula.

    The streak in the middle of the full scan is a scanner artifact (I've gotta take apart the Duoscan and clean it one of these days). The detail is at 1000 dpi.
    Attached Thumbnails Attached Thumbnails PL100-7.jpg   PL100-7dtl.jpg  
    flickr--http://www.flickr.com/photos/davidagoldfarb/
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  9. #69
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    Ochin Chorosho Davidovich.

    PE

  10. #70
    David A. Goldfarb's Avatar
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    Spasibo bolshoi.

    I thought I'd post the shot with 105 g/l hypo and no KBr for comparison. The light is better in this shot, so I thought that accounted for most of the differences, but I was looking at the negs more carefully, and this mornining, I'm thinking this version of the formula is a little better. More testing to do, I guess.
    Attached Thumbnails Attached Thumbnails PL100-5.jpg  
    flickr--http://www.flickr.com/photos/davidagoldfarb/
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