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  1. #1
    Flotsam's Avatar
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    I need longer Dev. times

    I've been using CPE to process my B&W film. The problem is that the continuous agitation seems to boost my contrast and cuts my times down to between 5 1/2 and 6 1/2 minutes. This is shorter than I would like and leaves no room for N minus development.

    I am considering increasing the dilution of my developer in an attempt to lengthen my developing times. I am currently using FG7 at 1:15.
    I know that I am going to have to retest my films but I am wondering if anyone has any thoughts on doing this or can suggest what I might expect.

    Thanks
    That is called grain. It is supposed to be there.
    =Neal W.=

  2. #2

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    Depends on the film and what process you are developing your negs for. Some films do not build contrast as rapidly or to as full an extent as others. I think that if I were faced with your situation then I would use a film and developer combination in which the testing has been done. I would look at the work that Sandy King has done on a variety of films as reported in the article on pyro developers on www.unblinkingeye.com

  3. #3
    gainer's Avatar
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    I don't know how much leeway you have for dilution before you run into starvation problems. If you think that might happen, a better way to get more development time is to reduce pH of the working solution. In the case of FG-7, I can't tell you much, but I think a small amount of boric acid might help. You could do a simple experiment with a scrap of film timed for two minutes or so. Add a measured amount of boric acid and see how long it takes to get the same density on another scrap. You could also use citric acid or perhaps even vinegar.
    Gadget Gainer

  4. #4
    Jorge Oliveira's Avatar
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    I think the easiest to start would be to dillute the dev 1+30 and retest.
    If the results are not to your liking, then you may try the pH reduction test.

    Jorge O
    Curitiba - nice place to live, if you don't care about the weather...

  5. #5
    Flotsam's Avatar
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    I just ran a test roll and thought that I'd share the results in case there is any interest here.

    I cut the dilution from 1:15 with plain water to 1:24 (10ml to 240ml) and increased my time from 5 3/4 minutes to 9 minutes. The results are very good. The developer seemed to hold its activity and responded pretty much as expected. As with all slow films, The Pan F + doesn't tolerate over-development so I will probably back down to 8 minutes for my N development to hold my highlights down. This will still give me a long enough time for an N - 1 development. The experiment was a success that I will continue to use and expand to my other films.

    I posted a scan of a print from that roll in the Critique Gallery. It doesn't do a damned thing to illustrate the process change but it was a nice day and I like the photo
    That is called grain. It is supposed to be there.
    =Neal W.=



 

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