Why 2 different D-72 recipes and 2 different G-201 recipes from same source

Discussion in 'B&W: Film, Paper, Chemistry' started by Christopher Walrath, Aug 29, 2010.

  1. Christopher Walrath

    Christopher Walrath Member

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    I was going through my old Focal Press Encyclopedia and was looking at the M.-Q. charts and found an interesting anomoly. 2 different recipes each for Kodak D-72 and for Gevaert G.201. As follows . . .

    Gevaert G-201
    Warm Water - 500cc for both
    Metol - 0.4g and 1.5g
    Hydroquinone - 1.5g and 6.0g
    Sodium sulphite, anhyd - 12.0g and 50.0g
    SOdium carbonate, anhyd - 8.0g and 32.0g
    Pottasium Bromide - 0.5g and 2.0g
    Add cold water to make - 1L for both

    I just noticed that the second recipe is nearly 4 times the strength of the first. Is this a concentrate?

    Kodak D-72
    Warm Water - 500cc for both
    Metol - 0.5g and 1.6g
    Hydroquinone - 2.0g and 6.0g
    Sodium sulphite, anhyd - 7.5g and 22.5g
    Sodium carbonate, anhyd - 11.0g and 34.0g
    Potassium bromide - 0.3g and 0.9g
    Add cold water to make - 1L for both
    And I have just noticed that the second recipe here seems to be roughly three times the strength of the first. So same supposition. Concentrate?

    Also, both first recipes are listed as standard contrast. Both second recipes are listed as, simply, 'Contrast' developers.

    Just curious but would love your thoughts and ideas.
     
  2. Ian Grant

    Ian Grant Subscriber

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    First because sometimes the Formulae are given at the working strength not the concentrate, that goes for both G.201 and D72. Often it was done for comparative reasons, it's what's in the final working solution you need to compared. So they are exactly the same Formulae.

    With D72 and 3 or 4 other Kodak packaged developers the weights in the commercial formulae were rounded off for Kodak consumer publications.

    Kodak had different recommendations for D72 in the US and UK, it's classified as a Contrast developer in the UK, and it wasn't recommended for papers and was sold as a film developer at one time, instead Kodak recommended D163 for papers. Later that changed

    Ian
     
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  3. Christopher Walrath

    Christopher Walrath Member

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    Thanks, Ian. Appreciate it alot.