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  1. #1
    mrred's Avatar
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    Chromium Intensifier

    I found this recipe on the net.

    distilled water -- 75 ml
    potassium dichromate -- 9 gr
    hydrochloric acid -- 6.5 ml (more to reduce intensity)
    add cold water to make 100 ml

    I tried it and it works quite well. My question would be how long would this stuff last on the shelf?
    Get it right in the camera, the first time...

  2. #2

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    This formula is intended for one-time use. As such it has little reserve capacity and should not be saved. For safety reasons not something that should be kept on the shelf.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  3. #3
    mrred's Avatar
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    What I stated is the stock formula. It is then mixed 1:10 for use, and that is one time use.
    Get it right in the camera, the first time...

  4. #4
    mrred's Avatar
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    Outside of it containing dichromate and hcl, does it create an additional combined hazard?
    Get it right in the camera, the first time...

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    What would be the advantages of this formula over the more standard selenium-toner, for negatives? (I'm assuming that you were using it on film, rather than paper).

  6. #6
    Ian Grant's Avatar
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    Quote Originally Posted by MartinP View Post
    What would be the advantages of this formula over the more standard selenium-toner, for negatives? (I'm assuming that you were using it on film, rather than paper).
    It's very much stronger in it's intensification.

    Ian

  7. #7
    mrred's Avatar
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    +1 and you can repeat it. I also had everything to make it.
    Get it right in the camera, the first time...

  8. #8
    Ian Grant's Avatar
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    In two parts the Chromium Intensifiers last decades. Ideally you need a Bichromate solution Part A and a weak HCl solution as Part B.

    Ian

  9. #9
    mrred's Avatar
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    I guess the magic approach is to split them up and do 1:1:20. Thats workable. It's just not something you would use every day, hence my question.
    Get it right in the camera, the first time...

  10. #10

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    That formula is for a ready to use, one-shot intensifier. It works well. You bleach the negative in the solution and then redevelop in something like Dektol.

    Kodak IN-4 chromium intensifier
    Water 1 l
    Potassium dichromate 90 g
    Hydrochloric acid (conc) 64 ml
    Dilute 1:10 for use. Bleach negative thoroughly in the above solution. Wash 5 minutes, then redevelop in room light in a non-staining developer without excess sulfite. Degree of intensification may be controlled by degree of redevelopment. After redevelopment, rinse negative, fix, and wash. Repeat process for greater effect.

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