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  1. #21
    dr5chrome's Avatar
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    Sounds like you've drawn your own conclusions. Thats what makes the darkroom fun. You've also picked a good film to start with.

    dw

  2. #22

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    Quote Originally Posted by dr5chrome View Post
    Sounds like you've drawn your own conclusions. Thats what makes the darkroom fun. You've also picked a good film to start with.

    dw
    Is there any difference between using a silver halide solvent in the first developer or after the clearing step?

  3. #23
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    Quote Originally Posted by Alessandro Serrao View Post
    Is there any difference between using a silver halide solvent in the first developer or after the clearing step?
    In principle, no. It just needs to be done before fogging.

    Note that the clearing step itself can also have a certain silver solving effect. That's why the overall composition of all solutions need to fit together.
    There is nothing like Scala? There are various alternatives!
    http://www.apug.org/forums/forum228/...cala-200x.html

  4. #24

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    Quote Originally Posted by amuderick View Post
    - CLEARING BATH

    30g Sodium Metabisulfite
    1L distilled water

    Generates sulfur dioxide gas which can be irritating. Ventilate this step!
    An ascorbic acid solution (at ~75g/L) can be used as a non-toxic alternative for the nasty metabisulfite clearing solution.

  5. #25

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    An ascorbic acid solution (at ~75g/L) can be used as a non-toxic alternative for the nasty metabisulfite clearing solution.
    Hologram -- clever idea. Do you see any development of the positive image when using ascorbic acid? Do you buffer the solution at all?

  6. #26
    dr5chrome's Avatar
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    .. i actually do feel bad about not sharing what the dr5 soup and procedure is, contrary to many who believe otherwise. dr5 is different than anything posted on this forum. It has been advised by several highly regarded photo people we keep this under our hat until we stop providing it as a service or retire.

    but i will give you this to your question... i would'nt use the mentioned solvent at all in a reversal process. you already know how i feel about the bleach

    regards

    dw


    Quote Originally Posted by Alessandro Serrao View Post
    Is there any difference between using a silver halide solvent in the first developer or after the clearing step?

  7. #27

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    Quote Originally Posted by Jordan View Post
    Hologram -- clever idea. Do you see any development of the positive image when using ascorbic acid? Do you buffer the solution at all?
    I am familiar with holographic emulsions mostly, which could be considered sort of high resolution black an white emulsions.
    At the low pH of that ascorbic acid solution (> pH 3.0) development does become very slow. But to be on the safe side you'd rinse your film, to remove the ascorbic acid.

    I've never used buffered solutions.

  8. #28

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    SULFURIC ACID does not attack stainless steel.

  9. #29

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    @Lowell -- Perhaps we are both right about the sulfuric acid and stainless steel: http://www.finishing.com/152/90.shtml
    I've had no problems myself and don't think anyone will with the low concentrations we use and the brief exposure.

    @dr5 -- Your process is a trade secret and you should keep it secret as long as it generates profits for you. We are all curious, I'm sure. I respect your choices and applaud your participation even to this extent. Personally, I look forward to sending some film your way once I graduate from test rolls and fiddling, if only to see the high bar you set! Thanks!

  10. #30

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    Quote Originally Posted by Lowell Huff View Post
    SULFURIC ACID does not attack stainless steel.
    It's too general an answer.
    It depends on what type of stainless steel we are talking and what sulfuric acid concentration is taken into account.

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