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  1. #1

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    what process came before C-22 if any?.

    I was curious as to whether there was any process that preceded C-22 if any?. I googled "kodak colour processes for colour negs" and got a whole lot of vague material but no definitive answer.

    Doug

  2. #2

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    All the information I can find seems to point to the color negative process prior to C-22 was just refereed to as Kodacolor Processing. Below is some of the information I found (for revision two of the Kodacolor processing):

    The film had a black and white contrast “mask” layer between the yellow filter later and the green sensitive layer. The mask layer was a very slow speed, blue sensitive emulsion, too slow to be affected by any camera exposure. The film was processed to form a dye negative image in each of the three colour coupling layers. The film was then exposed to blue light through the base, printing the already developed cyan dye and magenta dye layers onto the mask layer. The exposure did not affect the blue sensitive top layer because the yellow filter , underneath the blue sensitive layer would “stop” any blue light. The mask layer was then processed in a soft working black and white developer to form a weak positive mask image of the shadow areas of the green sensitive layer and red sensitive layer. The exposure of this layer took place after the film had passed through the Bleach bath. The idea was, when the negative was printed onto Kodacolor paper, obviously through the base of he film,the mask would have held back some of the exposing light from the shadow areas of the negative, thus lowering the contrast. The processing sequence may have been something like the one used for the original Kodacolor film outlined above but with additional steps.
    Developer Forms a dye image in the three colour coupling layers
    Stop-bath or Wash
    Bleach The Bleach bath converts the exposed and developed metallic silver (camera exposure) to silver halide so it can be made soluble in the Fixer. The Bleach works only on the exposed, developed silver halide so the mask layer is unaffected
    Re-Exposure The film is re-exposed to blue light to print the two developed dye forming layers onto the mask layer. The film is exposed through the base
    Black and White development The Mask layer is developed in a soft working black and white developer
    After black and white development and before fixing the film may have looked like this from the emulsion side downwards:
    Yellow layer – Bleached exposed silver halide.
    Yellow Filter - Still present.
    Mask layer - Developed but not fixed.
    Magenta layer – Bleached exposed silver halide.
    Cyan layer – Bleached exposed silver halide
    Fixer, performs the actions itemised: 1. Colour Negative. Removes silver halide formed by Bleach in exposed dye layers to leave pure dye.
    2. Colour Negative. Removes silver halide in unexposed dye layers.
    3. Black and white positive mask. Removes silver halide in unexposed black and white layer to leave positive mask.
    4. Removes yellow filter layer (or it is also possible that the yellow filter layer might have been removed in a separate bath inserted between steps 8 and 10 (see below), or it may have been removed in the black and white developer.
    The Fixer leaves exposed metallic silver in the mask layer as this was not turned into removeable silver halide in the Bleach. All silver halide is removed from the negative dye forming layers to make a colour negative.
    So I have also found reference to "Type B Processing" and "B-41" processing for EKTACOLOR (Yes, color not chrome) and "Vericolor Processing" for Type S and L Vericolor (1) film (Prior to Vericolor II/III which used standard C-41) the B and B41 processing certainly predates C22 but I believe that the Vericolor Processing was around at the same time as the C-22 processing.
    Last edited by septim; 12-10-2013 at 03:27 AM. Click to view previous post history.
    Shooting film doesn't make me a hipster, it makes me someone who takes photos...

  3. #3

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    Hi, there is a little bit of history in this thread: http://www.apug.org/forums/forum40/3...ss-b-41-a.html

  4. #4
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    As far as I am aware, the Vericolour I films used the same processing as the amateur films. I expect that the labs who processed a lot of Vericolour I probably were pro labs, with high volumes and increased quality control efforts, so a reference to Vericolour processing may have been a reference to the quality control procedures used by those labs.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  5. #5

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    what process came before C-22 if any?.

    Thanks Mr. Bill for that info. I remember when I worked at B.G.M. colour lab in Toronto in the mid to late 70's when we were in the process of converting from C-22 to C-41 that we kept getting film marked "Vericolour" no I,II, or III and someone pointed out that it was process C-22 not C-41. Before that, some of this film accidently made it into C-41 and gummed up the processor because of the temp. differences.

    Doug

  6. #6

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    I've never seen anything about Kodak's proprietary Kodacolor process; septim's comments are quite a revelation. The bleach used must have been similar to the bleach for black and white reversal films, removing developed silver but leaving undeveloped halide. The method of producing the mask is quite innovative. Unfortunately, the product was not so great.



 

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