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  1. #1
    Mustafa Umut Sarac's Avatar
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    Gasparcolor Film and Ilfochrome relation Question

    I am reading Google and found that Dr.Gaspar was the inventor of Ilfochrome paper. I found a article and it was 72 speed RGB turning Wheel movie taking camera invented by Gaspar and his friends. I learned that he was using two color one side and one color other side print film. I dont know but these are not great inventions , even an school boy could invent them.

    What was his major discovery ? What makes Ilfochrome print so jewel like ? What was the relation with RGB Movie and Ilford paper ?

    Umut

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    Gaspar invented a working dye-destruction (chromolytic) print process. Some of these prints still exist in beautiful condition. But there were
    several major refinements involved before Ciba commercially revived the concept decades later. So technically, he did not invent Cibachrome
    or Ilfochrome, but was one of several people working in a predecessor mode. Basically, the medium was saturated with particular dyes during
    manufacture, then exposed in the direct-positive mode & developed, after which a strong acid bleach removed the unwanted dyes. This is
    entirely different from negative exposure onto chromogenic papers, with the dyes being chemically formed during the chemistry steps, or the
    contemporaneous "assembly" color processes like carbro and dye transfer. There is a lot of interesting history behind all this - but I'm certainly no scholar on it. RGB is simply the additive exposure mode, used for Technicolor filming, for example; but I even use it for exposing
    chromogenic papers, as well as previously for Ilfochrome - that is, in distinction from ordinary subtractive YMC enlargement.

  3. #3
    AgX
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    Gaspar was the first to commercialize dye-destruction technique.

    Furthermore he was inventive on several fields of colour photography.

  4. #4
    Mustafa Umut Sarac's Avatar
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    If dyes being destroyed , what gives the colors ?

    Thank you,
    Umut

  5. #5
    Mustafa Umut Sarac's Avatar
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    bleach removed the unwanted dyes.
    I understood now , thank you . By the way, I researched carbon or dye transfer process and relief gives more freedom and pallette to grades. Is there such a relief at ilfochrome or similar trick ?

    Umut
    Last edited by Mustafa Umut Sarac; 06-07-2013 at 03:26 PM. Click to view previous post history.

  6. #6
    AgX
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    The resting dye density
    Think of the chromogenic dye technique where dyes are built up from zero density to their max. density depending on the image.
    With the chromolytic (dye-destructive) technique it is just the other way round.

  7. #7
    Mustafa Umut Sarac's Avatar
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    Thank you AgX , Is this paper manufacturable at home or are the dyes could be obtained and being ink jetted on to paper ?
    Thank you Drew by the way .

    Umut

  8. #8
    AgX
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    It is not the dyes alone. You need three halide layers including those dyes and get the silver-forming process coupled usefully to that dye-destruction.
    I would not consider it more easy than making a chromogenic three-colour paper.

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    Mustafa Umut Sarac's Avatar
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    What is halide AgX ? Do dyes needed to be chemically treated to obtain the colors finally ?

  10. #10
    AgX
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    With halide I refered to silver-halide, AgBr etc.

    In the presence of metallic silver, a low ph and a critical catalyst the dyes are bleached imagewise.

    There had been papers that only employed dyes, being directly bleached during the exposure. I guess their inherent disadvantages are obvious.
    Last edited by AgX; 06-07-2013 at 04:14 PM. Click to view previous post history.

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