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  1. #11

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    If there isn't any silver, reaction with selenium toner does not happen - at all. But... highlight area does have some silver - just not as much as mid tones or shadows. Unless you are saying a lot of silver works as a catalyst (catalyst speeds up the process - without being consumed in the process), then I still think, little silver in highlight area will reach completion much sooner than shadow because there isn't as much time needed to finish the entire reaction.

    My understanding is, direct sulfide toner (brown toner) is also said to work on highlight first. So the direct/indirect difference probably isn't a factor here... I think.

    I really would like to understand this....
    Develop, stop, fix.... wait.... where's my film?

  2. #12
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    Quote Originally Posted by tkamiya View Post
    If there isn't any silver, reaction with selenium toner does not happen - at all. But... highlight area does have some silver - just not as much as mid tones or shadows. Unless you are saying a lot of silver works as a catalyst (catalyst speeds up the process - without being consumed in the process), then I still think, little silver in highlight area will reach completion much sooner than shadow because there isn't as much time needed to finish the entire reaction.

    My understanding is, direct sulfide toner (brown toner) is also said to work on highlight first. So the direct/indirect difference probably isn't a factor here... I think.

    I really would like to understand this....
    Let's flip the coin. The absence of silver demotes the transformation of silver to silver selenide.

    Think of it like gasoline on water. If you set fire to it you will have lots of flames where there's plenty of gasoline, and very little, if any, where there's only a little. Why? Where there's a lot of fuel for the chemical reaction (rapid oxidation, or fire) to take place, it will happen quickly, but where there's little fuel, the reaction is a lot less violent.
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  3. #13
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    Could it be that the shadows aren't toning first? It may be that all that silver attracts more toner and it tones to a visible amount first. The highlights, comprised of smaller, more scattered silver particles, just aren't grabbing enough selenium to appear reddish but may be toning chemically. If one leaves the print in the toner long enough, it picks up enough selenium everywhere, and the print becomes visibly toned all over. But then this doesn't explain why some papers readily split while others, not so much, and sometimes not so red.

  4. #14

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    Thomas,

    Using your analogy, the area with less fuel burns less violently but will run out of fuel first. (complete toning)
    Develop, stop, fix.... wait.... where's my film?

  5. #15

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    Artonpaper,

    That makes the most sense - it's toning everywhere but we can't see it. HOWEVER, if that was the case toning shadow with one toner and toning highlight with something else won't be possible.

    The only way I kind of figured it may work is that the first toner tones everywhere at the same pace. So the highlight tones first and fully to pickup the color of the first toner. But, silver rich area of shadow aren't completely toned so when I use the second toner, it picks up the color of the second toner which over-powers the first. Since the highlight is already completely toned, there is no more silver left to pickup the second toner.

    In other words, neither toners are toning shadow or highlight differently. It's the matter of which one comes first. Once highlight is completely toned with one toner, it will no longer react with anything else. Stopping this reaction before shadows are completely converted allows the second toner to pickup the process for the shadow.

    I wish our chemists (I know they are there!) chimes in.... so I can stop guessing....
    Develop, stop, fix.... wait.... where's my film?

  6. #16
    Thomas Bertilsson's Avatar
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    Quote Originally Posted by tkamiya View Post
    Artonpaper,

    That makes the most sense - it's toning everywhere but we can't see it. HOWEVER, if that was the case toning shadow with one toner and toning highlight with something else won't be possible.

    The only way I kind of figured it may work is that the first toner tones everywhere at the same pace. So the highlight tones first and fully to pickup the color of the first toner. But, silver rich area of shadow aren't completely toned so when I use the second toner, it picks up the color of the second toner which over-powers the first. Since the highlight is already completely toned, there is no more silver left to pickup the second toner.

    In other words, neither toners are toning shadow or highlight differently. It's the matter of which one comes first. Once highlight is completely toned with one toner, it will no longer react with anything else. Stopping this reaction before shadows are completely converted allows the second toner to pickup the process for the shadow.

    I wish our chemists (I know they are there!) chimes in.... so I can stop guessing....
    I didn't realize you were asking about split toning.

    As long as you understand, you can play devil's advocate all you want. But the relationship between direct and indirect toners is what makes it possible, like I stated above. Why not send Wolfgang Moersch an email? Or Tim Rudman. From personal experience they are both receptive and helpful.
    I will check in Rudman's toning book for clues tomorrow, if I can manage to remember.
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  7. #17

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    In my experience, some papers show tonal change in the shadows first with selenium, but some tone much more evenly. I suspect the following is happening:

    Different papers, i.e., different emulsions, tone at different rates and by different amounts.

    Many (most) papers, and all VC papers have two or more emulsion components in them.

    It stands to reason, that these may tone at different rates and by different amounts.

    If your highlights are composed largely of silver grains of a particular size and configuration stemming from one emulsion component, but the shadows have silver grains of a different size and shape from another emulsion component, then split-toning (or dual-toning if you prefer) is readily understandable.

    Example: The older formulation of Seagull G papers (a graded paper) toned very evenly to a uniform eggplant/reddish color. Just a hint of this was really nice for a feeling of depth. The formulation changed when cadmium was banned, and the toning characteristics of the paper changed: different image tone, but still relatively even. Then, the formulation was changed again: Seagull G became GF. In this last formulation, the grade 2 paper split-toned rather heavily (and unpleasantly for my taste), but the grade 3 still toned evenly and to a different color than the grade 2. I'm not sure what the cause of all this is, but I'd put my money on emulsion formulation and different amounts of different size and shape of silver grains in the shadows as opposed to the highlighs. Now, Seagull G is gone, discontinued as so many other fine papers .

    I would imagine that the activity of selenium toner on a homogenous emulsion would be even, i.e., with all portions of the print toning at the same rate. The only thing that would make the shadows tone more slowly (and the highlight areas tone to completion first) would then be exhaustion of the toning solution in the more dense areas, similar to the effect of compensating developers. I don't know if this happens, but I suspect not. In that scenario, it would take longer for the shadows to tone than the highlights, which does not seem to be the case in my experience. This could be tested easily if one had a paper with just one emulsion component (or a completely bleached/rehalogenated print). I may try the test when I get back to the darkroom this summer.

    In addition, there are also the optical effects to be considered. In dense areas, the selenium color would predominate, since the entire area would be getting toned. In highlight areas, however, there is a lot of paper base showing through, with a color of its own, that is not getting covered by selenium toning. In very light areas, only a small percentage of the total area is actually being changed in tone; the paper base does not change color, so the overall tone change is less than in the darker areas. This obviously could contribute to the impression that the shadows change image tone before the highlights.

    And now, start combining these effects and what do you get? It is always more complicated than we think.

    Best,

    Doremus

    www.DoremusScudder.com

  8. #18

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    It can help to think of Selenium as an intensifyer. The degree of toning is proportional to the amount of silver present, whether toned partially or to completion. This is why it works as a proportional intensifyer for negatives (ie contrast increase). Metallic silver converted or coated with Selenium blocks light more efficiently than untoned metallic silver. Hence the contrast increase in selenium toned negatives, and the enhanced d-max in papers.

    Regarding the differences in toning properties of papers in Selenium (degree, color), there are several factors. In addition to all the emulsion characteristics, my understanding is the degree to which the emulsion is hardened in manufacturing also contributes considerably.

  9. #19
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    Wolfgang Moersch has showed some great photos with Holga 120N. I could not believe at first that they were shot with that camera.
    OM-1n: Do I need to own a Leica?
    Rolleicord Va: Humble.
    Agfa Isolette III: Amazingly simple, yet it produces outstanding negatives.
    Holga 120GFN: EV 11 or EV 12.

  10. #20

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    Quote Originally Posted by Thomas Bertilsson View Post
    I didn't realize you were asking about split toning.

    As long as you understand, you can play devil's advocate all you want. But the relationship between direct and indirect toners is what makes it possible, like I stated above. Why not send Wolfgang Moersch an email? Or Tim Rudman. From personal experience they are both receptive and helpful.
    I will check in Rudman's toning book for clues tomorrow, if I can manage to remember.


    Just so we are clear - I am not playing devil's advocate. I am trying to understand the WHY portion of these processes so I can use them to my advantage. I happen to have couple of prints right now that I think would be a good candidate for split toning. So far, the results are disappointing. It is one thing to take conventional wisdom and use it - but it is another to understand the reason behind those wisdom and really take an advantage of it.
    Develop, stop, fix.... wait.... where's my film?

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