pyro tri

Discussion in 'B&W: Film, Paper, Chemistry' started by archer, Jul 13, 2009.

  1. archer

    archer Member

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    Thanks to everyone who responded to my post regarding clearing times in hypo. I now want to tell you about an experiment I just performed on the Efke 50. In 1984 I mixed a litre of the pyro tri developer recommended by Paul Farber in Peterson's Photographic. I had never used it since I first mixed it and just found it in the back of my chemical cabinet, among those bottles that always seem to get moved and never used. I was ready to dump it and mix some fresh, when I decided to look at it. After pouring it into a beaker, I was surprised to see that it looked the same as the day I first mixed so I saved it and mixed a fresh batch and out of curiousity developed two identically exposed sheets of film, one in each developer. To my utter amazement they looked identical even under my microscope at 100x. Since I don't have a densitometer I used my Colorstar 3000 to check the density range of both negs in my enlarger and they were virtually identical. Does anyone have any experience with this developer and can you tell me what you think of it? Is this stuff immortal?
    Thanks,
    Denise
     
  2. gainer

    gainer Subscriber

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    Don't even know the formula.
     
  3. Ian Grant

    Ian Grant Subscriber

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    It's Obscure, I took this from an APUG thread a few months ago

    Farber's PM-TEA

    Oxalic acid 1.8 g
    Potassium metabisulphite 4.5 g
    Pyrogallol 54 g
    Metol 19 g
    Sodium sulphite 135 g
    Triethanolamine 140 ml
    Distilled water to make 4 litres

    Can't vouch for how accurate it is.

    Ian
     
  4. nworth

    nworth Subscriber

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    I have a slightly different formula. The reference for it is ""Petersen's Photographic," July 1984, pg. 84.

    Oxalic acid 1.5 g
    Potassium metabisulfite 3.5 g
    Pyrogallol 46 g
    Metol 16 g
    Sodium sulfite 116 g
    Triethanolamine 120 ml
    Water to make 4 l
    Dilute 1+1 for use. Develop Tri-X 5-1/2 minutes at 21 C

    Photographers' Formulary lists yet another formula:

    Metol 17.8 g
    Oxalic Acid 1.7 g
    Potassium Metabisulfite 4.3 g
    Sodium Sulfite 140.0 g
    Pyrogallic Acid (Pyro) 51.2 g
    Triethanolamine 133 ml
    Water to make 1 gallon of concentrate. Mix chemicals in order given.

    I used it for a while, and I found it to be an excellent developer. Note that this is a non-staining pyro developer. The original article noted that it had excellent shelf life. I can verify that, as long as it is kept well sealed in an air-tight bottle. I gave up using it mostly because of its oddball ingredients.