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  1. #31

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    am I the only one who is confused as to how the fully developed silver from step one is removed by fixing later?

    edit: Oh, duh. all the developed silver becomes re-sensitized and so then soluble in fixer if not developed out.

  2. #32
    Herzeleid's Avatar
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    copper chloride bleaches the fully developed silver and then re-halogenates it. Re-halogening is the key, for example potassium ferricyanide bleach does not re-halogenate the silver. Correct me if I am wrong.

  3. #33

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    If Ferricyanide bleach doesn't rehalogenate, why does it contain potassium bromide?

    I was rather hoping it does rehalogenate.

  4. #34
    Herzeleid's Avatar
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    Sorry, for the confusion I was referring to a single pot. fer. cyanide solution, not its combination with potassium bromide.

  5. #35

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    why fog the film?

    I remember reviving some old bromide paper by soaking it in potassium permanganate solution and then washing it. The idea was to oxidise any silver metal particle, hence reverse the effect of exposure to light or other radiation which occurs after prolonged storage.Only a tiny proportion of the emulsion would have been converted to metallic silver so once the silver had been removed the remaining emulsion would work normally.I had some success with this.

  6. #36

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    Fanshaw that is rather interesting. Without wishing to take the thread too far off topic, could you give a few more details? Was it simply a solution of permanganate in water? if so, what weight/volume?

  7. #37

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    This is interesting, kind of a variation of what I raised in post #18, except I contemplated developing the unexposed,fogged film first. But doesn't developer just act as an amplifier? Perhaps Fanshaw is suggesting something like just bleaching the unexposed, undeveloped film to treat the miniscule amount of latent silver, unamplified by development?

    Would the permanganate have been used with sulfuric acid or sodium bisulfate, as used some times with reversal bleaches?

    And what about using a rehalogenating bleach instead?

    I may try this with my old FP3.

  8. #38

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    Unfortunately I can't remember the permanganate concentration. I am sure however that it was just permanganate solution without additives.

  9. #39
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    hmm...rather confused on this one

    I recycled another spool of 35mm Valca 6 Din using the same process as in my first post, only this time I used Dektol 1:3 instead. After determining in the darkroom that my film speed is around .0015 ASA I wanted to put my calculations to practice, and after taking a few bracket shots I decided why not try some taking some with color filters. Now, when I developed the film I was surprised to see that my photo taken with the red 25 filter came out at all, I mean in the end, isn't re-hal film just blue sensitive? I know about the phenomena that happened with the first tricolor photograph (Maxwell) but as you can see in the red filter positive both the red tail-lights and a red sticker on the trunk came out, plus look at the golden leaves on the tree to the left of the garage.
    Click image for larger version. 

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ID:	81988 UV filter f1.7/8s Click image for larger version. 

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ID:	81989 Green (58) filter f1.7/16s Click image for larger version. 

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ID:	81990 Red (25) f1.7/64s
    So just out of curiosity, I combined the three negatives in Photoshop (I know I cheated digitally, but I didn't tweek any levels or anything, I just combined the positives in rgb color layers and then aligned them) and I got a color image! Click image for larger version. 

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ID:	81991 In theory, this shouldn't be happening right? Any insights?
    Last edited by yurisrey; 02-11-2014 at 12:05 AM. Click to view previous post history.
    "The real work was thinking, just thinking." - Charles Chaplin

  10. #40
    yurisrey's Avatar
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    correction: I should've measured for .005-.006 ASA hence why they're a stop over
    "The real work was thinking, just thinking." - Charles Chaplin

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