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  1. #1
    pierods's Avatar
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    Metol-only developer?

    What would happen if one omitted Sodium Sulfite from d-23?

    Meaning:

    Distilled Water (125 degrees F) . . . . . . . 750 ml
    Metol . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 g
    ̶S̶o̶d̶i̶u̶m̶ ̶S̶u̶l̶f̶i̶t̶e̶ ̶(̶A̶n̶h̶y̶d̶r̶o̶u̶s̶)̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶.̶ ̶1̶0̶0̶ ̶g̶
    Cold Water to make . . . . . . . . . . . . . . . . . . 1 ltr


    As far as I understand, SS is only used as a preservative, so I suppose that the only changes would be:

    - less fine grain
    - it should be used one-shot
    - one should mix it every time

    Would it work under these conditions?

  2. #2
    Rudeofus's Avatar
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    Quote Originally Posted by pierods View Post
    What would happen if one omitted Sodium Sulfite from d-23?

    Would it work under these conditions?
    Most likely not. Don't forget that sulfuric acid is a weak acid (especially with regard to its second proton), therefore Sodium Sulfite is mildly alkaline. If you leave out the sulfite, you will have to add at least something to compensate for this.
    Trying to be the best of whatever I am, even if what I am is no good.

  3. #3
    pierods's Avatar
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    Uhhmm...

    Well, how low can I go then with the SS? Meaning, so to change PH but forgetting the preservative part? Or - what to replace it with?

  4. #4
    David Lyga's Avatar
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    You could ALMOST eliminate it. Few realize just how little sulfite is needed if you take precaution to keep the developer airtight (glass or PET plastic filled to the rim). I could get away with using only about 5 grams per liter. And you will have a sharper image too, because the sulfite will not be 'destroying' (softening) the silver grains.

    But take a good look at the contrast which might be lower because of the lack of hydroquinone. Really, there is little better than the marriage of metol and HQ.

    Yes, pierods, PH is important to consider here since sulfite is actually alkaline. Add a bit of carbonate, maybe one gram or so. - David Lyga

  5. #5
    pierods's Avatar
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    Thanks David:

    So finally you suggest 7.5 g Metol + 5 g SS + 1 g carbonate OR 7.5 g Metol + 1 g carbonate ?

  6. #6
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    Developer substances work only in alcalic medium. It is not necessary to protect the metol if you prepare the solution fresh from powder chemicals. But you need something which gives a mild alcality at least. Borax is possibe if you want avoid sulfite.
    ---
    Uwe Pilz

  7. #7
    pierods's Avatar
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    Excellent. How much?

  8. #8

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    As far as I understand, SS is only used as a preservative
    NO!

    Thee role of sulfite in a developer is a very complex one.

    While the sulfite content of a developer can be reduced it cannot be eliminated entirely. There are several reasons for this. Metol is a hydrochloride salt and is acidic. Enough base must be added to a developer to neutralize any acid from the metol. In many formulas the sulfite acts as the only base to raise the pH so that the metol can develop. Secondly without any sulfite a developer will likely produce stains on the negatives. I would suggest looking at the Crawley FX-1 formula for an idea of a minimalist sulfite developer. Thirdly, some sulfite must be present or film speed will suffer. Sulfite acts as a silver halide solvent and thus exposes active sites to the developing agent. There are more reasons which will not be discussed here.
    Last edited by Gerald C Koch; 10-09-2012 at 10:25 AM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

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  9. #9
    pierods's Avatar
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    I looked, the fx-1 formula says 50 g SS.

    But it also says 5 g metol (instead of 7.5 for d-23), why?

    Also, what is the iodide for? [I checked that too - "Mr. Crawley claims the Iodide's action is to enhance adjacency effects", I'll skip that]
    Last edited by pierods; 10-09-2012 at 10:27 AM. Click to view previous post history.

  10. #10

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    This developer is diluted for use so the actual sulfite content is 5.0 g/l. There is some argument whether the iodide is necessary or even useful in a developer of this type.

    This developer is a variant of the Beutler formula which uses 10 g of sulfite in the working solution. Crawley found that this could be reduced to 5.o g/l. He was a careful and thorough experimenter. I would speculate that he found this value to be the minimum which would produce good results.
    Last edited by Gerald C Koch; 10-09-2012 at 11:06 AM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

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