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  1. #11
    holmburgers's Avatar
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    It's good, and I appreciate the description. Though I don't understand how "all" the silver can be developed in the 1st dev and yet leave a positive image of undeveloped silver that is necessary for the CC-developer to oxidize and create dyes. I guess by all you just mean most?

    What I'm attempting to say is this: how can we reversal process C-41 without resorting to simply putting it through the E6 process. Specifically, when in the process & how can we safely remove/desensitize the oxidizable media (negative silver image) before it is CC-developed?

    Does that make sense, or am I just whistling dixie?

    edit: Thanks Kevs. To be honest, I don't have a result in mind at the moment, and the idea of having a masked positive is actually a good thing in my eyes, since it helps with color reproduction. My thinking is that a reversal processed negative film with mask would be the finest scanning medium; having fine grain and color corrective masking. The orange mask could be compensated for "computationally" (that sounds better than digitally... hahah)
    If you are the big tree, we are the small axe

  2. #12
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    Well, I should have been more specific.

    The first developer is designed to develop all of the silver that comprises the negative image (directly exposed Silver Halide) and the color developer is designed to develop all of the remaining Silver Halide.

    Yes, you can process C41 film in E6 to get a low contrast masked color transparency, but I doubt if any scanner is capable of handling it well. A scan of a color negative might be better. A masked slide would be hard to print as well being so low in contrast.

    PE

  3. #13
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    Well, just putting it through E6 is what I'm trying to change; doing that brings us right back to typical X-pro. It seems to me that using the appropriate color developer (CD-4) would yield better results, no?

    Hence, "cross-processing", but not really...
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  4. #14
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    I am really not sure what you want to do.

    Sorry.

    PE

  5. #15
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    Here is my train of thought, if it's not clear...

    A C41 emulsion is designed to work with a developer containing CD-4, so it seems that putting it through a process that uses CD-3 is not ideal. I'm just trying to surmise if an alternative processing scheme utilizing a CD-4 developer as a 2nd developer can yield a positive in a way that is different from typical cross-processing, which is simply running a C41 film through the standard E6 process.

    If I'm embarking on a dead end path, just tell me...

    I guess what made me think of this was reading about making separation negatives. The integral masking in C41 films makes it so that no masking is necessary in the separation stage, whereas a slide, with it's admittedly imperfect dye set (for making separations), requires color-corrective masking in the separation stage. If I want to enlarge to a separation negative on panchromatic film, having a masked positive would be a boon, but the cross-processed results are of such questionable quality that this isn't a viable option.
    If you are the big tree, we are the small axe

  6. #16
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    Yes, you can make an E6 color developer using CD-4. It will affect dye hue and image stability. The thing is, that the fundamental dye structures were intended for printing, not viewing and so at a later stage in the mechanical process, you would have to correct for this.

    PE

  7. #17
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    Hmmm... but I want to make a reversal process for C41 using CD-4, having nothing to do with E6. It sounds like you're referring to processing E6 in CD-4, no?

    If we develop C41 film in a contrasy b&w developer as a 1st dev, can we remove that negative silver image safely, and then utilize a CD-4 developer to bring out the remaining positive image?
    If you are the big tree, we are the small axe

  8. #18
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    Ok, make a positive from C41 film using ANY process with ANY color developing agent will give a low contrast positive of some sort, but the dyes are not adjusted for the human eye, but rather for the use of a print material.

    Go here: http://www.kodak.com/global/en/profe...4051/e4051.pdf page 5 and look at the sensitivities and the dyes. Now go here: http://www.kodak.com/global/en/profe...4024/e4024.pdf and compare the same things. You will see a big difference in spectral sensitivity and in the hue of the dyes. These differences attempt to match the reversal film to the eye and the negative film to the print materials on the market. The print materials have dye sets that are more like the reversal film to remove any hue shifts or other color errors.

    PE

  9. #19
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    That is a very illustrative comparison and I see what you mean. It's interesting that the Portra curved doesn't show the individual dye curves, but it makes sense in light of what you're saying.

    I am not concerned with this theoretical C41-positive's visual appearance, but I am concerned with having "separable" layers. I'm looking at this from the perspective of scanning and/or making color separation negatives onto panchromatic film. In either instance, as long as the color channels are discrete enough that they can be separated from each other through the use of filters or computationally, its visual appearance is not important really.

    Issues with dye-stability and masking are what I'd like to preserve in a C41 positive.

    As usual Ron, thanks for taking the time to humor my queries..
    If you are the big tree, we are the small axe

  10. #20
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    Well, if you are scanning, you can fix color errors by digital masking.

    And, I am always glad to try and answer questions.

    PE

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