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  1. #1
    Mustafa Umut Sarac's Avatar
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    Negative Autochrome Film Screen in Afghan Camera with Negative Color Paper

    I found a idea and want to ask your opinions.


    1. First of all lets solve making autochrome screen making problem without investing tens of thousands to patent blue dye.

    2. I am thinking to buy a very fine quality autochrome 3''X4'' plate , than remove its bw emulsion and contact copy the autochrome RRGGBB screen on to 4x5 negative color film.

    3. Than c41 develop the negative color film and secure the negative at somewhere.

    4. Next step is to build a Afghan Camera working with color negative paper..

    5. Lets take out our autochrome screen copied negative film and put it in front of afghan camera's lens.


    Two big question ,

    What would be the final image of negative paper. Would it be a positive ?

    Mustafa Umut Sarac
    Istanbul

  2. #2
    Photo Engineer's Avatar
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    Presumably, this would give a positive. I have said before that I had never seen an additive neg-pos system but Holmburgers posted one. So, I guess they could be made. I will have to work out the polarity-color issues before I can be sure of making a print though.

    OTOH, Autochromes are so poor in quality, IDK what would result.

    PE

  3. #3
    Mustafa Umut Sarac's Avatar
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    Thank you PE , Someone posted a stainless Afghan Camera thread and I really loved the idea. Can I develop color negative paper or film in the camera or the temperature margins are so high ?

    Umut
    Last edited by Mustafa Umut Sarac; 04-21-2012 at 06:42 PM. Click to view previous post history.

  4. #4
    Photo Engineer's Avatar
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    Don't develop it in the camera. It is too corrosive.

    PE

  5. #5
    Mustafa Umut Sarac's Avatar
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    Thank you PE , I worked at a photo house 25 years ago and inside of a cramped darkroom where thete was a automobile size paper development machine and we were working with that dinosaur. It has may be 100 liters developer inside and we breathed all the fumes.
    I forgot all the details and I dont know anything about c41. Does paper development was really that corrosive ?

    Umut

  6. #6
    EASmithV's Avatar
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    Correct me if i'm mistaken, but wouldn't the autochrome screen need to be directly contacting the film between the lens and film, not in front of the lens?
    www.EASmithV.com

    "The camera is an instrument that teaches people how to see without a camera."— Dorothea Lange
    http://www.flickr.com/easmithv/
    RIP Kodachrome

  7. #7
    Stephen Frizza's Avatar
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    sorry see below
    "Its my profession to hijack time" ~ Stephen Frizza.

  8. #8
    Stephen Frizza's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    Presumably, this would give a positive. I have said before that I had never seen an additive neg-pos system but Holmburgers posted one. So, I guess they could be made. I will have to work out the polarity-color issues before I can be sure of making a print though.

    OTOH, Autochromes are so poor in quality, IDK what would result.

    PE
    I played with this, the two main problems i had are as follows, using panchromatic black and white film you have to be careful of just how sensitive the film is to certain areas of the spectrum as it if has bias in say the yellow green the screen must accommodate this etc... tying to balance an incorrect screen to film ratio with a neg process would be a huge head ache in my opinion. Secondly the resolution is an issue. the image at 1:1 looks good but enlarging it breaks down. I think first everyone should perfect screens as a pos system then venture into neg.
    "Its my profession to hijack time" ~ Stephen Frizza.

  9. #9
    Stephen Frizza's Avatar
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    Quote Originally Posted by Mustafa Umut Sarac View Post
    I found a idea and want to ask your opinions.


    [*=center]I am thinking to buy a very fine quality autochrome 3''X4'' plate , than remove its bw emulsion and contact copy the autochrome RRGGBB screen on to 4x5 negative color film.


    Mustafa Umut Sarac
    Istanbul[/B]
    This Can NOT BE DONE. Autochrome plates are not RGB and the nature of the coating process in an autochrome is randomized, getting the donor registered in future tests on such a complex dispersion will be extremely difficult. This is a very bad approach.
    "Its my profession to hijack time" ~ Stephen Frizza.

  10. #10
    Photo Engineer's Avatar
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    The Autochrome process has less "quality" than the Dufay process and I am quite aware that as Autochromes (or Dufay) images are enlarged, they tend to break down and become very grainy. Evan at 1:1, an Autochrome looks worse than a Dufay image.

    There are ways to balance the sensitivity of a film to a screen using color filters. This would increase the chance of success somewhat.

    For useful results the screen should be against the film, but in the above OP, I can see using 2 screens. One to replicate the original and one on the print material.

    PE

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