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  1. #1

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    New film developer idea (all powder!)

    Iím setting up a film processing station in my new commercial photo studio. I think Iím going back to all powder formulation, like I used to with DS-1 and DS-2. For small scale film processing, powder formulation offers more advantages than liquid concentrates, including long keeping properties. Iíd rather weigh powder mix than viscous stock.

    Iíd probably formulate like this:

    Part A:
    ascorbic acid
    Phenidone (or Dimezone S)
    one or more water soluble polymers (cellulose derivatives, vinyl derivatives, and of course polyvinylpyrrolidone) and/or sugar alcohols (sorbitol, xylitol, etc).
    any other additives

    Part B:
    sodium sulfite
    borax
    developer stabilizer additive

    The only tricky part here is how to ensure uniform mix and prevent segregation in Part A. I think one or more water soluble polymers with suitable molecular weight and particle size can be used to ďdiluteĒ Phenidone first, wherein the Phenidone and polymer form cohesive aggregates. This is then mixed with the rest of ingredients in Part A. With this level of care in formulation, it is okay to just stir the jar before use.

    Some of the water soluble polymers are actually known to improve image quality. Viscous developers are known to increase accutance and reduce granularity, although incompatible with spiral tank processing. Iím probably going to use polymers that are not viscous for this project, but something that has other effects, such as lower fog level and cleaner highlights. In the past, I experimented using several kinds of polymers in liquid concentrate stocks, but these polymers do not dissolve well in a concentrated sulfite solution. So, I often had to add them to the working solution. Powder formulation can just solve that problem altogether.

    Another advantage of powder formulation is that we donít need glycols and other solvents, and donít need to handle viscous liquids. About the only and small negative is that I have to give up my favorite ethanolamine mix and go back to Borax.

    If this approach works, I think itís just a matter of stirring powder mix A in a jar, take 6 grams, take 50g of B, dissolve in a liter of cold tap water, adjust the temperature and itís ready to go. (Numbers are just made up but they are realistic range.) This will be easier to dissolve than D-76 (stuff will dissolve while loading films into tank). Iíd probably keep mix A in a vacuum jar to prevent moisture caking and oxidation.

    Added bonus is that I can have a Part C, which can be used in place of Part B, to make a different developer. Iím most likely making Part B for fine grain (400+ speed films) and Part C for accutance (100 speed films), just like what I used to do with DS-1 and DS-2.

    What do you guys think?

  2. #2

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    Won't you just run into the old issue of particle separation due to bulk density? I suppose if your polymer can be coated uniformly then you have a chance of it working.

    How's this idea - find a matrix that is soluble in both solvent and water and then dissolve your phenidone and ascorbic into it with the solvent. Pour the solution out into a tray and let the solvent evaporate. Then grind the matrix to a fairly uniform particle size so that it quickly dissolves in water. Then you can pretty much be assured of uniform distribution of your developing agents in your matrix.

    Kirk

    PS - glad to see you back here!
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  3. #3

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    Quote Originally Posted by Kirk Keyes View Post
    Won't you just run into the old issue of particle separation due to bulk density?
    Thatís more likely if sulfite and borax are mixed together with developing agents, so I expect less problem with my strategy. But it remains to be tested.

    How's this idea - find a matrix that is soluble in both solvent and water and then dissolve your phenidone and ascorbic into it with the solvent. Pour the solution out into a tray and let the solvent evaporate. Then grind the matrix to a fairly uniform particle size so that it quickly dissolves in water. Then you can pretty much be assured of uniform distribution of your developing agents in your matrix.
    Thatís too much work :-)
    Itís more work than weighing individual ingredients each time I develop.

    If this were a $500k/yr business, Iíd probably use a tablet press to punch out tablets. But Iím looking for a good small scale processing solution...

  4. #4
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    This lot does my head in - If you only process BW in small batches get some Rodinal, not the magic brew some claim, but it does work - Leave your head clear for making images

  5. #5

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    Ryuji


    too bad it has to be mixed / suspended into a liquid
    i have often wished there could be just a powder to submerge
    my film into, no liquids ... and
    after " x minutes " it would be ready to fix ...
    when i read the title of your thread, i thought my wish had come true !

    happy holidays !
    john
    ask me how ..

  6. #6

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    Quote Originally Posted by jbaphoto View Post
    This lot does my head in - If you only process BW in small batches get some Rodinal, not the magic brew some claim, but it does work - Leave your head clear for making images

    hi jbaphoto:

    you might not realize .. but Ryuji is an inventor of developers
    and maker of emulsions ... i haven't used his magic brews
    but from all reports they work well, very well !

    john
    ask me how ..

  7. #7

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    Quote Originally Posted by jnanian View Post
    too bad it has to be mixed / suspended into a liquid
    i have often wished there could be just a powder to submerge
    my film into, no liquids ... and
    after " x minutes " it would be ready to fix ...
    when i read the title of your thread, i thought my wish had come true !
    Ha! I don't know how to do that but that's not a bad idea... It'd be hard to pour powder to your tank though.

  8. #8

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    Quote Originally Posted by Ryuji View Post
    It'd be hard to pour powder to your tank though.
    That's where your Jobo rotary processor comes in handy!
    Kirk

    For up from the ashes, up from the ashes, grow the roses of success!

  9. #9

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    I actually never owned a Jobo. It'd be a good idea but it's still expensive...

  10. #10

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    This sounds quite interesting, I wish you complete success with it.

    Experimenting with developers is nothing but fun in my opinion-
    I would love to use the "FP" flash setting on my camera, but I cannot find "Flash Powder" anywhere... such is life.

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