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  1. #1

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    Metol-Glycin two bath experiment

    Hello

    Here is some results of my experiment. I'm starting from simple formula:

    Bath A:
    Sodium sulfite 60g
    Glycin 7g
    Water 1l

    Bath B (one shot):
    Potassium carbonate 10g
    Water 1l

    developing time 5+5min. very tiny image, loss more than 2 stops. so I was modify formula and add some amount of metol:


    Bath A:
    Sodium sulfite 60g
    Glycin 7g
    Metol 2g
    Water 1l
    pH 7.5(!)

    Bath B - same

    this variant work, but loss 1 stop and give me negatives with very low gamma (about 0.3). max density is low (zone 5 - 0.4, zone 8 - 0.75). this formula can't make density more than 1.6 over fog+base.
    next step - increase amount of metol:


    Bath A:
    Sodium sulfite 60g
    Glycin 7g
    Metol 7g
    Sodium carbonate 7g
    Water 1l
    pH 8

    Bath B - same

    reason of adding 7g of sodium carbone is very low pH 7.2 without it. developing Ilford HP5+ 400@400 3+5min. negatives look very nice. max density limited to 1..1.1 over B+F (zones 11..12). grain is fine. but sharpness is open question. follow is scan 2400dpi without any processing (only adjust min/max/gray levels) and some crops









    what do you think about this?

  2. #2

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    The reason why glycin does not work is possibly because metol is much more active.
    I have taken the attached approximation from "The Theory of the Photographic Process" Mees & James p361.It show the density obtained with metol and glycin after equal times of development.
    Attached Thumbnails Attached Thumbnails metol vs glycin-1.jpg  

  3. #3

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    Seems like what you're coming up with is something similar to FX2 (Metol-Glycin-Carbonate), but with higher sulfite so reduced acutance and finer grain.

  4. #4

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    Quote Originally Posted by Alan Johnson View Post
    The reason why glycin does not work is possibly because metol is much more active.
    I have taken the attached approximation from "The Theory of the Photographic Process" Mees & James p361.It show the density obtained with metol and glycin after equal times of development.
    I think that metol and glycin is superadditive. I found very interesting patent US2164280 by Lowe from far 1935. He describe next formula

    Metol 8g
    Glycin 8g
    Sodium sulfite 100g
    Ammonium chloride 5g
    Water 1l

    He state that pH 7.4 is preferable! Also he note that 2nd developer agent must have "low production potencial".

  5. #5
    CBG
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    I don't recall seeing any reference stating metol and glycin are superadditive. Does anyone have a definitive source on that? I have seen references stating that Glycin and phenidone are superadditive, just not metol/glycin.

    Regardless, the final mix seems like a D-23 variant, and looks like it would work fine as a two bath. I wonder if it would act nearly the same with the glycin entirely omitted.

  6. #6

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    Quote Originally Posted by Relayer View Post
    I think that metol and glycin is superadditive.
    No, they are not superadditive. According to Mason, the primary developing agent is always one of the nitrogenous agents (Metol, Phenidone are examples) and the regenerating agent is usually one of the phenolic compounds (hydroquinone, catechol, ...). Since both Metol and Glycin are in the first group there is no superadditivity.
    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

  7. #7

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    Quote Originally Posted by Alan Johnson View Post
    The reason why glycin does not work is possibly because metol is much more active.
    I have taken the attached approximation from "The Theory of the Photographic Process" Mees & James p361.It show the density obtained with metol and glycin after equal times of development.
    Yes, in a Metol/Glycin developer the faster acting Metol will do most of the developing. A developer based on only Metol and Glycin is really not the best combination of developing agents.
    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

  8. #8

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    Crawley forumulated FX2 on Metol and Glycin though. It's an excellent developer. Not sure what his reasoning was for combining Metol and Glycin.

  9. #9

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    Crawley introduced FX-2 in BJP Jan 6 1961. He did not give much explanation but here's a quote:

    "Earlier in this paper the old method of producing sharp negatives for lantern slide making-glycin stand development-was described......On modern slow and medium speed films,glycin with threshold energy supplemented by metol will give a high standard of sharpness and definition,but not marked adjacency effects in the strict definition of raised edge contrast.Such a metol-glycin developer is FX-2,which may be used,diluted, as a stand developer"

    He did not actually state it but adjacency effects can be obtained by reduced agitation.

  10. #10

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    I've read (in the Cookbook for example) that FX-2 makes a good developer for reduced agitation techniques. Perhaps Crawley's line of reasoning with Metol-Glycin included the reputation Glycin has for being resistant to mottle and streaking.

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