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  1. #1
    Ian Grant's Avatar
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    The Ilford PQ variants of ID-11 (D76)

    Most of the MQ variations of D76 are published widely, but less is known about the PQ variants of Ilford's equivalent developer ID-11

    Although J.D. Kendall of Ilford discovered and patented Phenidone (1-Phenyl-3-Pyrazolidone) in 1941 it was 11 years before the first packaged products containing it went on sale.

    Many of these first developers were simply Phenidone based versions of MQ developers, typical examples are ID-20 PQ and ID-36 PQ, and research into other possible developer combinations & formulae continued.

    In 1954 Ilford published the first formulae in The British Journal of Photography stating "As Phenidone is now generally available in bulk packings ranging from ¼-oz. to 4-lb., it is felt that the publication of a number of formulae in which this new developing agent is used in combination with hydroquinone will be useful to those workers who wish to compound their own developers".

    These developers were:
    ID-62 - a PQ variant of ID-20
    A very similar developer for Contact prints - (identical except the Potassium Bromide is cut to 0.25g/litre)
    ID-67 - a PQ variant of ID-2
    Fine Grain Developer for plates and films - a PQ variant of ID-11 - the formula below.


    Fine grain developer for plates and films (1954)

    Sodium sulphite (anhydrous) 100 gm.
    Hydroquinone 5 gm.
    Borax 2 gm.
    Boric acid 1 gm.
    Potassium bromide 1 gm.
    Phenidone 0.2 gm
    Water to make 1 litre

    Development time: 7-11 minutes at 68° F.

    This developer has characteristics approximating to those of Ilford ID-ll, but shows less change in activity during use.


    This PQ version of ID-11 was taken further by A.J.Axford & J.D.Kendall who published a version with slightly different buffering for commercial processing, and they included two types of replenisher.



    ID-68 was a reformulation of the Fine Grain PQ developer to give better film speed and is similar to Microphen, in Ilford's words "Phenidone as used in the formula below gives remarkably high emulsion speed with fine grain (approximately to ID-11 standards) with development times of 10-15 minutes at 68° F.
    This developer shows exceptionally small change of activity with use." Also "Development times as for Microphen"

    ID-68
    Ilford Phenidone-Hydroquinone Fine grain Developer


    Sodium sulphite (anhydrous) 85 gm.
    Hydroquinone 5 gm.
    Borax 7 gm.
    Boric acid 2 gm.
    Phenidone 0.13 gm.
    Potassium bromide 1 gm.
    Water to make 1 litre

    This developer may be used undiluted.
    "Development times as for Microphen"

    Here is a comparison of ID-11 (D76) and the Ilford PQ Fine grain developers:



    Axford & Kendall's Commercial "PQ Fine Grain Developer" formula has been incorrectly described as being of "Microphen type" in books and websites like Silvergrain, it is just a differently buffered version of the PQ ID-11 type developer Ilford published in 1954.

    Ian Grant 2008
    Last edited by Ian Grant; 07-25-2008 at 08:21 AM. Click to view previous post history.

  2. #11
    seawolf66's Avatar
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    Ian Grant : Thanks for info on the ID-11 developer, which I use
    Lauren MacIntosh
    When one's life Ends, then one becomes Life's history !

  3. #12
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    My o my, how did these digital pictures get here??
    If I had been present at the creation, I would have given some useful hints for the better arrangement of the Universe.
    Alfonso the Wise, 1221-1284

  4. #13
    Ian Grant's Avatar
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    An update on the Axford-Kendal PQ Fine Grain Film Developer

    Two papers, in 1956 & 57 looked at the effects of bromide and replenishment on this developer which by then had been released under the Autophen trade name. A third paper relates to testing procedures to determine Phenidone & Hydroquinone levels.

    Unlike ID-11/D76 the Axford/Kendal PQ - F.G.F. developer doesn't suffer from Bromide build up and needs a lower rate of replenishment as a consequence making it significantly more economic. Ilford ID-166 (D76d) was used as the reference standard.

    Tests were carried out in a commercial laboratory using a 24 gallon (UK) process line/tank and 65,000 rolls of film processed with topping up replenishment, giving consistent results. With MQ developers a bleed system of replenishment is required.

    That's 595 rolls of film per litre !!!! Who says replenishments not economic ?

    Ian
    Last edited by Ian Grant; 05-26-2010 at 11:12 AM. Click to view previous post history.

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