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  1. #1
    David A. Goldfarb's Avatar
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    I think we all know about experiments involving tea and coffee, which have natural tannins as developers, but the latest issue of _Photovision_ (July/August 2003) has a serious proposal for using the naturally occuring pyrogallol in brewed tea as a developing agent, and the results published in the magazine look pretty good. Two formulas are included, one similar to ABC and one a variant on PMK.

    Anyone try them yet?

  2. #2

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    David,
    I found the article interesting as well. I have found my results with Pyrocat to be all that I could hope for, at this point. I do agree with you that the results in the article do appear supportive of the benefit of using a readily available material.
    Art is a step from what is obvious and well-known toward what is arcane and concealed.

    Visit my website at http://www.donaldmillerphotography.com

  3. #3
    David A. Goldfarb's Avatar
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    Another interesting sidenote about that article was that the version of PMK used a sodium metaborate presoak.

    I was wondering about precisely this thing because I once accidentally forgot to add the A solution to a batch of PMK before pouring it into the tank. My normal procedure is for tank development is to mix up the water and B solution (sodium metaborate), then add the A solution (pyro-metol) to the beaker, turn off the lights, open the top of the tank, and pour it all in (because the tank fills slowly through the daylight cap), replacing the lid and proceding normally with the lights on. After recognizing my mistake, I added the A solution to the tank, and everything came out fine, but I wasn't sure this was a good practice.

    Now that I know that a sodium metaborate presoak is not a bad thing, I think I might repeat this "mistake" regularly, because it means I can do everything with the lights on.

  4. #4
    Loose Gravel's Avatar
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    I do the Kodalk presoak ever time. I put the stock 'B' in half the water and give 2 minutes of this. The I add the stock 'A' with its half of the water and start the clock. This has helped give even results although I use sheet film in a rolling tank.
    Watch for Loose Gravel

  5. #5
    Ole
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    Reversed divided developer? Now that's a novel idea!
    I did this by accident recently. Results were unconclusive as I develop by inspection: Fogged negatives...
    -- Ole Tjugen, Luddite Elitist
    Norway

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    Ole
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    Quote Originally Posted by David A. Goldfarb
    ...the naturally occuring pyrogallol in brewed tea as a developing agent...
    Are you sure the article said that? If tea contained pyrogallol it would be banned, I think. It does, however, contain Gallic acid and lots of other tannins.
    -- Ole Tjugen, Luddite Elitist
    Norway

  7. #7
    David A. Goldfarb's Avatar
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    More specifically, the claim was that gallo-tannic acid is inherent in ordinary green tea, and "upon sustained boiling, some of the gallic acid molecules in the tannin release and some may even change to pyrogallol."

    It's not a very precise description, but the prints look good!
    flickr--http://www.flickr.com/photos/davidagoldfarb/
    Photography (not as up to date as the flickr site)--http://www.davidagoldfarb.com/photo
    Academic (Slavic and Comparative Literature)--http://www.davidagoldfarb.com

  8. #8
    Ole
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    Gallic acid was much used as a developer in the days of the wet plate, so it doesn't surprise me that it works.
    Conversion to pyrogallol should not be necessary, nor do I think you could do that by boiling (but I may be wrong).
    -- Ole Tjugen, Luddite Elitist
    Norway

  9. #9
    David A. Goldfarb's Avatar
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    I suspect you're right, Ole. According to Gordon Hutchings, gallic acid needs to be heated to 210 degrees C. under pressure to drive off carbon dioxide and convert it to pyrogallol. This would require quite a tempest in a teapot.
    flickr--http://www.flickr.com/photos/davidagoldfarb/
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  10. #10

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    Why is it so hard? Doesn't CO2 like to come out of solution?

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