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  1. #11
    holmburgers's Avatar
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    So I contacted Photo Researcher, the guy who made that coating machine and is quoted in post #1. He told me that he's working on a Kodachrome-esque color film; and like PE, has successfully created the 3 emulsions necessary but has yet to "put it all together". It sounds like he is working very hard on it, and he isn't too fond of computers but hopefully he will drop in to share his progress from time to time. I encouraged him to do so.

  2. #12
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    I wish him all the best. I hope we hear from him soon.

    PE

  3. #13
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    http://www.apug.org/forums/forum205/...r-example.html

    Ron, stumbled upon this post. Anymore like it?

    edit: searching your posts....

  4. #14
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    No more color coatings at present. I am having a problem with mordanting the dyes. They tend to dissolve in the developer so I have to get them to stay put. Alum was my first bet, but I cannot coat it easily without crosslinking the gelatin as well as mordanting the dye. So, experiments continue, but I have no progress to report. I have searched a lot of old patents though.

    I find, as I expected, that the mordants we used at EK were often custom made.

    PE

  5. #15
    holmburgers's Avatar
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    Here is a thought, or series of them...

    What does one need in a color film? For me, it is the ability to capture the color information of a scene, in one exposure, in perfect registration and in any size, the larger the better. The size caveat is important in dismissing digital...

    For me, I have less interest in printing this picture on RA-4 or Ilfochrome paper, because I'm operating under the assumption that if I'm making a color emulsion, none of these great things will exist anymore, let alone color film, so why count on any paper being around? Carbon, carbro and dye-imbition (DCG) are what I'm hanging my hat on for the future, as the materials are for the most part independent of silver photography. And of course, scanning.

    So, with this in mind, the color emulsion need only have the color information stored in it, not necessarily the color appearance stored in it. What I'm getting at is, it doesn't matter what the color emulsion looks like, as long as the 3 color sensations are recorded and are separable by use of appropriate filters.

    Point being, all color films have sought to reproduce the scene as realistically as possible, since they were either slides or designed as negatives to print on a similar material coated on paper. But had someone been making a film designed for one of the separation methods, or today, where digital capture and "decoding" is an option, the film image need not resemble the scene in color.

    I don't know enough about separation filters, efficiency thereof, overlap, etc., to say if such a scheme could work; but if one is making a color emulsion and their stumbling block is the appearance of the dyes, it might not matter afterall. As long as they are different enough to be discernible in some way.

    Correct me if I'm wrong, but Gasparcolor utilized a scheme where, as a printing film, it could not be utilized for direct capture. Instead, separations were printed onto it using blue, red(?) and infrared light to reach the sensitive layers. This is of course entirely different from what I just proposed, but it's an example of "thinking outside the box" in terms of color emulsions.

    This is all theoretical of course, but I hope what I'm getting at makes sense to some degree.
    If you are the big tree, we are the small axe

  6. #16
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    You must use R/G/B exposures to capture the original either by using a 3 color camera or a tripack.

    Printing can use any color combination as long as R = Cyan, G = Magenta and B = Yellow from the original. However, other mehtods such as your blue, red and IR, although workable give us a film that is very very difficult to work with and which will keep poorly.

    PE

  7. #17
    holmburgers's Avatar
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    Thanks PE,

    Certainly, the film must capture the 3 color sensations, red, green and blue; but their end color is where I'm saying there is room for "slop", or flat out "false color", as long as there is a way to separate them optically from one another.

    The blue, red, IR was just an example, something that I read in relation to Dr. Bela Gaspar, but honestly I don't know what the final Gasparcolor product was like.

  8. #18

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    If all you want to do is read the data from a tri-color pack film, you could consider a method that was used in a 'quick process to scan' machine that flopped several years ago due to the rapid emergence of the digital camera. I forget the name of the machine or who marketed it. Perhaps it had something to do with the people who developed 'digital ice'.

    Basically it worked something like this: (I may be wrong on several points here) -

    The film was developed in a B&W developer, which developed the three silver images. I don't think that a color developer was used, but I'm not sure. I'm not sure if they fixed it either. They ran the wet film into a scanner which scanned the front and the back at the same time in a reflective mode (obviously they had to remove any AH layer). They also scanned through the entire film (reading the OD of all three layers). From these three scans, they were able to obtain RGB values, the center layer was calculated by subtracting the densities of the two outer layers from the total transmitted density. I believe that the results were quite good, but it was a one shot process - the film was rolled up still wet, and sent out for silver extraction.

    Regards - Jim Browning

  9. #19
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    Wow,

    I've never heard of such a thing, to say the least. I'm not even sure if I understand it, but I'll do some digging around. Indeed, that is the only requirement I'm suggesting; to get RGB values from 1 exposure.

    Thanks for sharing!

  10. #20

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    Maybe you could find out more by searching for patents held by the company that does 'Digital Ice'.
    Applied Science Fiction?

    Regards - Jim

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