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  1. #1

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    Dignan NCF-41 Divided Color Negative Developer

    In the NOV/DEC 1995 issure of Darkroom and Creative Camera Techniques
    Patrick Dignan wrote an article on a divided color negative developer. Everything in this article comes from that source.

    Patrick Dignan, sadly now deceased, was a pioneer in the formulation of color chemistry for the home darkroom worker in the United States. As such he had earned the respect of an extensive following of home darkroom workers in compounding their own color chemistry. This article is the result of work that he did...thank him not me.

    Of course as a divided developer there is al lteast two baths: Developing agent etc in bath A and the alkali etc in bath B. The reason for having two baths is that when the baths are combined oxidation starts with the predictable effect one must expect on shelf life. This type of developing practice of two...or more..baths has been long practiced in b&w for the same reasons. In the case present it is to provide a divided alternative to C-41 (Flexicolor) developer.

    A BATH:
    Water (distilled) 300milliliters
    Sodium Bisulphite .5 (1/2) gram I added (1/2) to prevent reading as 5 grams.
    CD-4 (Kodak developing agent) 5.5 grams
    Sodium Sulphite (anhy.) 4.5 grams
    Water (distilled) to make 500 milliliters
    ph at up to 75ºF: up to 6.5
    Time in A bath (including drain time): 3 min.


    B BATH
    Water (distilled): 500 milliliters
    Potassium Carbonate 53 grams
    Potassium Bromide .5 (1/2) gram
    Water (distilled) to make 1 liter.
    optional: Benzoitriazole (Kodak anti fog #2) 2 milligrams
    Ph at 75ºF: 11.8

    Time in B bath 6 minutes

    As you can see not a difficult formula to put together. There is no need to be able to measure any closer than 1/10th gram

    Shelf life has exceeded 1 year. Use an acetic acid stop bath. I, in lieu of anything else, I would recommend 20% vinegar to water
    Coventional bleach and fix or blix as otherwise used. 75ºF can be used with extended time.

    Since there is some carry over every time film is developed you will eventually find your self with insufficient stock to cover your film. That is when you will need to make more. The amount of time elasped from compounding should not matter. NEVER GET ANY B BATH INTO A BATH OR YOU WILL CAUSE THE A BATH TO START OXIDIZING.

    THIS DEVELOPER IS DESIGNED TO WORK WITHOUT A PREWET BATH
    Since the time in A bath is used only to absorb developing agent and because the agent will be fully utilized in B bath you can not over develop your color film.

    This is designed for tank processing. I do not see a method for use with a JOBO unless you reclaim your ingredients.

    Try this as it is aseasy and as economical as you will ever find.

  2. #21
    Athiril's Avatar
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    I know this is old, but this keeps coming up in my search results and I've been intrigued.

    HAS should not be needed as a preservative though? Unless it performs any other function in a developer other than to preserve it?

    My reasoning is that Flexicolor Developer replenisher comes in 3 parts, part C contains the CD-4 in an acidic pH and no HAS and has a really long shelf life - longer than mixed solution, part B contains the HAS. So my thought is its not needed in an acidic pH condition (such as Bath A in the recipe).

  3. #22
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    I am dubious about any divided developer. It relies on the swell of the film to imbibe the correct amount of developing agent for action in part B. This amount will vary with hardness, and with the amount of gelatin coated (thickness). So, the actual formula and conditions will not be correct with every film and may be way out of date with current films.

    Note the pH of part A. It is only slightly acidic. This may not be enough to stabilize the CD-4 for long term keeping, but in any event, the HAS is not in the developer portion of the C41 kit IIRC.

    Pat and I talked a lot about this back in the days he was writing. He lived near here and we talked on the phone and exchanged letters.

    PE

  4. #23
    Athiril's Avatar
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    Is the film thickness (coated gelatin) related to the contrast of the film? I mean rather than influencing contrast, is it decided that higher contrast films will have a thinner/thicker coating?

  5. #24
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    Thickness and contrast are generally not related. It has more to do with design for a given purpose and in some cases coating restraints.

    PE

  6. #25

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    I tried this years ago, and it seemed the fewer layers in the film, the less crossover. So some very
    sophisticated films with several layers, like some Kodak, would have much thinner layers to avoid
    transmission problems. More layers, more different speeds, harder to co-ordinate,more crossover.
    It might be tweakable for consistent results with a two-layer mono film. I have heard that the new
    Ektar is only three layers, but fine grain means thinner layers, so there we are again. I might be
    more inclined to separate RA-4, but making trouble early in the process is big trouble later.

  7. #26

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    I found that same method (2batch color developer) described in patent US3869288 by Leopold Godowsky in 1973

  8. #27

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    Hi there,
    I'm looking at this recipe to use in a Rondinax 60 but am struggling to find sodium bisulphite. Can I use a slightly reduced quantity of Sodium Metabisulphite as an alternative?

  9. #28

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    According to rudeofus Sodium Metabisulphite is interchangeable with Sodium Bisulphite. He referred me to this archived web page
    Thanks rudeofus

  10. #29

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    Hi Adrain

    We are interested in how you get on with this.

    And Id note PE's caution about the layers/diffusion, you are going to have to white balance in PS.

    The HSA can be an active developer chemical as it is (or a close analogue) at the bottom of the list of development chemicals in complexity.

    But it is omitted from the cine negative film developer, which does use CD3 as well.

    Good luck

    Noel

  11. #30

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    I've got nearly all the gear for this, I'll give it a bash tomorrow (if there's any light to take some snaps by).

    I think you can substitute Sodium carbonate (which is what I have) for Potassium carbonate at ~0.8 by weight - is that about right?

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