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  1. #11

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    Helen -- I've never tried packaged paper developers -- I don't print at home so I don't keep them at hand. But Ilford has a PDF on their site about reversal processing that starts from Bromophen or PQ Universal to make a first dev.

    Jordan

  2. #12
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    Jordan,

    Yes, it's quite common to use a paper developer. Maco suggest their LP-BROM 4 for reversing PO100c, for example

    Best,
    Helen

  3. #13

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    Quote Originally Posted by Helen B
    Jordan,

    Yes, it's quite common to use a paper developer. Maco suggest their LP-BROM 4 for reversing PO100c, for example

    Best,
    Helen
    Right, I think I've seen MACO's instructions too. BTW, check your e-mail for my reversal info.

  4. #14
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    I just noticed that to buy Potassium Dichromate you have to have a DEA Authorized Buyer Form on photographers formulary, though I'm not sure if I need a DEA registration number.

    Has anyone else run into this? Is there somewhere to buy the kit already made up?

    Thanks,

    William
    "I know of no country in which there is so little independence of mind and real freedom of discussion as in America." -- Alexis de Tocqueville

  5. #15
    Helen B's Avatar
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    Why not just switch to a permanganate reversal bath?

    Best,
    Helen

  6. #16
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    Quote Originally Posted by Helen B
    Why not just switch to a permanganate reversal bath?

    Best,
    Helen
    You need the form for sulfuric acid too. Wierd. I don't think you need a DEA registration though.

    William
    "I know of no country in which there is so little independence of mind and real freedom of discussion as in America." -- Alexis de Tocqueville

  7. #17

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    Sulfuric acid is pretty nasty stuff. Battery acid is sulfuric acid and may be easier to find locally. IIRC the strength of sulfuric acid in a typical bleach bath is around 2%. You could use sodium bisulfate (note: not sodium bisulfite) as a substitute -- it is a solid that dissolves in water to produce what is effectively a sulfuric acid solution. But it may be expensive or hard to get.

    FWIW, here is my first-dev recipe based on HC-110 (slightly ad-hoc as shown by the mixed units):

    Start with about 400 ml water and add:

    6 tsp sodium carbonate
    15 ml HC-110 syrup (concentrate as sold in North America)
    2 g potassium bromide (anti-fogging agent -- may not be necessary)
    8 g sodium thiosulfate
    make up to 500 ml in water

    I found that 8.5 mins at 24C gave good results (E.I. ~64) with Ilford Pan F Plus using a permanganate bleach, metabisufite clearing bath and thiocarbamide re-fog.

    Jordan

  8. #18
    rjr
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    Helen,

    Quote Originally Posted by Helen B
    I downloaded Liam's original article a while ago, but I have no idea which country my copy is in, never mind which disk it is on.
    If you ever find it again, would you mind sending me a copy?

    I recently worked on an instruction sheet for developing Agfa Scala in the commercial Foma Slide kit (works very decently!) and plan to give a from-scratch approach a try.


    Quote Originally Posted by Helen B
    I hope that people change from a bichromate bleach to a permanganate bleach (and a compatible clearing bath - the clearing bath should be chosen according to which bleach is used).
    Well - many people messed up the KMnO4 bleach... they prepare it too early and mix it with tap water, resulting in a reaction of the bleach with minerals in the water ("Braunstein") and thus spots on the film. Instead I´d recommend using demineralised water, mix is shortly before usage and to filter it. We had no problems at all after using this approach.

    Tetenal once sold a commercial slide kit - they changed it from dichromate to KMnO4 but made an error. It was sold premixed, the permanganate and the sulphuric acid came in a single pack and many people learned the hard way that this sometimes resulted in a nonfunctional bleach. Tetenal finally broke down and stopped selling the kit. :-(

    Quote Originally Posted by Helen B
    Best,
    Helen
    Thanks,
    Roman
    Tschüss,
    Roman

  9. #19
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    As a matter of interest, pHMinus for swimming pools is sodium bisulfate and is not very expensive.
    Gadget Gainer

  10. #20

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    Quote Originally Posted by gainer
    As a matter of interest, pHMinus for swimming pools is sodium bisulfate and is not very expensive.
    Patrick, this is great to know. Thanks for sharing it. I may yet have another go at the B&W slide process at home.

    Roman, I didn't know that Foma made a reversal kit. That's also great to know. My chances of finding it for sale here in Canada are pretty much nil, though.

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