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  1. #1

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    A concentrated, Phenidone-only developer (J. D. Kendall)

    I find this interesting as it is the only developer I know of other than POTA using only Phenidone as a developing agent. The patent by Kendall (U.S. Pat. 2,289,367) is from 1942. My source for the formula is Modern Photographic Processing by Grant Haist (vol. 1, Special-Purpose Developers, Concentrated Developers, p. 523).

    Composition:

    3g 1-Phenyl-3-pyrazolidone (Phenidone)
    25g Sodium sulfite (crystalline)
    50g Sodium carbonate (crystalline)
    0.5g Potassium bromide
    500ml Water to make

    Dilute 1+3 for use.

    Depending on the hydration state of the sulfite and carbonate available, the following ratios can be used:

    -For anhydrous sulfite, multiply the crystalline amount by 0.5 (= 12.5g anhydrous sulfite in the above formula)
    -For anhydrous carbonate, multiply the crystalline amount by 0.37 (= 18.5g anhydrous carbonate in the above formula)
    -For monohydrated carbonate, multiply the crystalline amount by 0.43 (= 21.7g carbonate monohydrate in the above formula)
    Last edited by Michael R 1974; 03-05-2014 at 09:21 AM. Click to view previous post history.

  2. #2
    Ian Grant's Avatar
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    I have it as a Phenidone equivalent of ID-3 (similar to Selectol Soft/D165) it's adjusted to make 1 litre:

    Example 1

    Phenidone 6 gm.
    Sodium sulphite (anhyd.) 25 gm.
    Sodium carbonate (anhyd.) 37.5 gm.
    Potassium Bromide 1gm.
    Water to make 1 litre

    To use 1+3

    Results are similar in characteristics to a Metol only developer using the same weight of developer,
    only softer.

    It's unusual as it has a very high level of Phenidone unlike the usual substitutions.

    All the examples in the Patent are Phenidone substitutions for Metol in existing Metol or MQ formulae, so ones a Phenidone/Pyrogallol developer.

    Ian

  3. #3

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    It would be interesting to test this formula. Substitutions of Phenidones in place of Metol are viable when the developer contains a secondary superadditive agent, but I would not expect using Phenidone only in place of Metol in a Metol-only developer would work very well, if at all. For example, you cannot make a Phenidone-only version of D-23.

    Perhaps the relatively high pH of this formula helps, but I'd still expect either very low contrast or high fog. An interesting formula.

    I'll post a few other interesting Axford/Kendall things from Haist in separate articles.



 

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