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  1. #51

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    Quote Originally Posted by johnielvis View Post
    I doubt explaining the mechanism of why something produces brown is giving away any secrets. I suspect it's all due to small silver particles too.

    right--I think it's teeny developed grains too--or physically deposited teeny silver particles...

    so it should be easily removed with a post ferricyanide bleaching step....as I suspected.

    I just want to know if the bleaching worked--the original poster seems to want to keep quiet on this. It would be nice to confirm my suspicions. However, the silence may also speak volumes as well...

    bluh....done with this booyah
    johnielvis. I'm not keeping quiet - I just haven't been able to do any work on developing recently. In the meantime, I'm spending what time I have on another aspect of my project . So I just do not have an answer. With regards the E6 bleach idea, I'm reluctant to go out and buy a whole E6 kit for this one test.

    You're theory on the length of time of the 2nd dev is interesting - have you confirmed it?

  2. #52
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    dr5

    ..not to despair. We are working on a possible "dr5-kit". Other than those close to the lab, this is the 1st It is mentioned here. If it's feasible, it might happen. dw



    Quote Originally Posted by Rudeofus View Post
    I can hardly blame DR5 for not giving away his trade secrets, quite to the contrary, I'm impressed he responded here at all.

    I do have a theory about Rodinal and brown silver: in the FD step you have a strong solvent which completely removes tiny grains but leaves not so tiny grains behind as tiny grains. Tiny grains would normally either
    • not develop at all because they are very insensitive to light
    • be dissolved away by any moderately solvent developer

    Now all of a sudden we have a strong re-exposure step which makes sure these tiny grains are exposed and will develop, too, and we have a more or less non-solvent developer (Rodinal) which happily develops them into tiny (and therefore brown) Silver crystals. DR5's suggestion to use a developer high in HQ (i.e. high contrast, i.e. won't develop tiny grains) and high in Sulfite (i.e. dissolves tiny grains before they develop) would certainly point in that direction.

  3. #53
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    Quote Originally Posted by dr5chrome View Post
    ..not to despair. We are working on a possible "dr5-kit". Other than those close to the lab, this is the 1st It is mentioned here. If it's feasible, it might happen. dw
    If this kit will resemble the Foma reversal kit in any way, please supply it with instructions that say: "Undissolved Permanganate grains in the bleach will leave ugly brown spots on your slides. Permanganate takes forever to dissolve, so please plan accordingly when you prepare the bathes."
    Trying to be the best of whatever I am, even if what I am is no good.

  4. #54

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    Quote Originally Posted by dr5chrome View Post
    p-amino phenol hydrochloride, which is the main developing agent in rodinal, tends to have this brown color in the final image. There are several important factors when it comes to final image color. Even a new agent from another factory can cause color-tone shift. Other things as simple as the water you use +++, etc.. The best neutral result "with the developers used": I would stick to a developer [1st & 2nd] with a high concentrate of HQ and sulfite. Most films will have a good 'neutral' with such a developer.

    dw

    dr5.com
    Thanks for this explanation. I didn't notice it before.

    The reason I was interested in R09 as a developer was that it appeared to be even more active than the Dokumol that I had been using. With it, I could reduce the amount of hypo needed to get similar results to the Dokumol with 4x the hypo . So, with R09, I felt was getting a bit closer to the 'dream' of a silver-solvent free 1st dev. And that is something I believe that you have achieved at dr5 - even though no one knows how.

    And so, to answer your second post – I, for one, would be interested in a dr5 home kit.

  5. #55

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    I'd be quite interested too !

  6. #56

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    Funnily enough after some successful reversal processing I started getting yellowy/brown images since reading this thread. This was occurred both with second exposure and development and with chemical reversal. At first I thought it was the bleach and/or clear as it was getting a bit old but on renewing that, same result. This pointed to the first developer, I use Suprol, and the bottle had been open for quite a while. With fresh developer, the tint went away. But, what is interesting is that with slightly oxidised first developer I was even getting the stain with chemical reversal (using "Iron Out", not using that developer.

    Thanks, for the tip on the ferricyanide bleach/fix, johnie, I wasn't clear on the recipe 'pure hypo 1:1' seems a low dilution , i.e. strong concentration of hypo, but I added the ferricynaide to my usual solution of hypo and it did brightened up the images on the the strips I tried.

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