Home brewed Pyro HD

Discussion in 'B&W: Film, Paper, Chemistry' started by scootermm, Jul 23, 2005.

  1. scootermm

    scootermm Subscriber

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    For the last year Ive been ordering my Pyro HD from photographers formulary. It came in 500ml A and 500ml B liquid solution.
    After starting to shoot 7x17 and developing my negatives in trays with DBI, Ive found I go through the 500ml fairly fast. So I referenced the unblinkingeye.com article by Sandy and just order bulk chemicals from Artcraft to mix it up myself. I used distilled water... heated it to mix solution A, mixed solution B like normal (ended up with a pinkish/wheat color)

    alright my question is, Im finding Im getting 'flatter' negatives than I normally do. Ive been shooting JandC photo 200 for a while but in comparison to the premixed liquid Pyro HD I was getting from PF the negatives seem flatter now that Im using the homebrewed Pyro HD. any idea what may have or could have caused this? Also the developement time for proper highlight density and shadow density seems a little faster with the home brewed mixture.

    Thanks in advance.

    PS also one more question. I purchased 3lbs of Citric Acid today to use as a stop bath for my film. how much powder should I add to 1Liter of water? (one spoonful, two?)
     
  2. sanking

    sanking Member

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    Actually, most of the comments I have received in comparing the commerical liquid kits, both B&S and Formulary, is that they give less contrast than when mixing the chemicals from scratch.

    I will remark that very small differences in the actual amount of bromide and phenidone in the solution, which can easily happen when mixing the developer in small quantities, can make a very significant difference in energy level. For example, when mixing the stock solutions in amounts of one liter or less I use a scale with an accuracy of 0.01.

    To compensate for this batch just plan to increase development time by 50% or more based on previous work.

    Sandy
     
  3. Jorge

    Jorge Inactive

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    I suspect there was some confusion in the concentration of the pat B solution. A "100%" solution (which it is really not but close enough) is made by mixing a 100 gr of potassium carbonate and adding water to make a 100 ml. In the unblinking eye instructions it says to add 100 gr of potassium carbonate to 100 ml of water. This makes approx a 75% solution. If you are seeing your negatives a little bit flat I would say if you use 1:1.2:100 of your mixed formula you will see the same results as your PF kit.

    Good luck.