Base colour of cross processed film? Fuji RAP/Astia 100

Discussion in 'Fuji' started by Nick Zentena, Jul 3, 2004.



  1. No, I said OMIT the reversal bath!
     
    Michael Scarpitti, Jul 5, 2004
    #21
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  2. No, doesn't anybody understand? C41 is essentially E-6 after the revrsal bath...
     
    Michael Scarpitti, Jul 5, 2004
    #22
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  3. No, no, no:

    http://www.kodak.com/global/en/prof...j83/j83.jhtml?id=0.1.16.14.30.14.3.26.3&lc=en

    Read the steps following the statement:

    'Remaining steps can be done in room light.'
     
    Michael Scarpitti, Jul 5, 2004
    #23
  4. Its not quite the same. The second developer has a fogging agent
    in it which will make all silver halide on the film developable
    regardless of whether its been exposed or not.
    Here is how reversal color processes work.

    First step, a black and white silver image is developed in the three
    layers (some films have more layers). After the first development each
    layer has a silver image and the undeveloped halide. The color
    couplers are not converted to dye because the developer does not have
    the right components to react with the coupler to produce it.
    Second step in modern processing is the _second developer_. This
    developer differs from the first developer in that it has the
    following two items: 1, a fogging agent; 2, the right stuff to react
    with the couplers to produce dyes.
    After the second development _all_ the silver halide in the film is
    converted to metallic silver but a positive dye image also exists in
    the areas where the second development took place. The second
    developer is selective because no halide exists in the areas already
    developed into a negative by the first developer. As a result, the
    second developer, which includes the color formers, works only in the
    other areas, resulting in a positive image.
    The third step is the bleach or bleach fix. This converts the
    metallic silver back to a halide and removes it. This can be done in a
    single solution called "blix" or in separate bleacher and fixer. The
    bleaching bath and fixing bath do not affect the dye image.
    If one omits the first developer and uses the second developer the
    results will be the conversion to silver of _all_ the halide in the
    film AND all the dye. So, you will have a black image even if the film
    is subsequently treated in blix to remove the metallic silver image;
    the dye will remain.
    If the film is developed in the second developer it will result in
    development of all the silver at once because of the fogging agent.
    Where a fogging agent is not included in the second developer the
    film must be fogged with light between the two development stages.
    In black and white reversal processing the process is somewhat
    different because the final image is formed of metallic silver rather
    than dye. For B&W the film is developed in a normal developer, the the
    silver image is removed by a bleach that dissolves metallic silver but
    not the remaining halide. This leaves a positive image composed of
    halide. This halide is made developable by either fogging with light
    or by a fogging agent in the second developer. The result is a
    positive metallic silver image.
    In the case of color negative film the "base color" is NOT in the
    support but is, as I explained in an earlier post in this thread, due
    to the color couplers themselves being colored. The coupler not
    reacted to form image dye remains its original color which is chosen
    to be a masking color to correct the transmission faults of the dye.
    These colored couplers are not used in color reversal materials. They
    can have an overall color cast due to processing problems like
    contamination. Neither does the support of either color negative or
    color reversal film have any pigment in it, its perfectly clear as one
    can demonstrate by removing all the gelatin, emulsion and backcoating,
    in a bath of household bleach.

    Richard Knoppow
    Los Angeles, CA, USA
     
    Richard Knoppow, Jul 5, 2004
    #24
  5. Nick Zentena

    Nick Zentena Guest


    Following up. The negatives may be TOO dense. I'm thinking the next test
    will be at 100 EI and not 50-)

    Nick
     
    Nick Zentena, Jul 5, 2004
    #25

  6. No, it doesn't. That's the Reversal Bath, step 2, which I say to SKIP.
    Kodak
    E-6 Color developer does not have a reversal chemistry in it. Perhaps
    Tetenal or other chemistries do, but not Kodak.

    http://www.kodak.com/global/en/prof...j83/j83.jhtml?id=0.1.16.14.30.14.3.26.3&lc=en

    Solution/Step Time1 (min:sec) Temperature┬░C (┬░F) Comments
    Lower Limit Aim Upper Limit
    Perform these steps in total darkness.
    First Developer2 5:00 6:00 7:00 36.7 to 39.4
    (98 to 103) Recirculate and filter. Nitrogen agitation.3
    First Wash 1:00 2:00 4:00 33.3 to 39.4
    (92 to 103) Air agitation.3
    Reversal Bath 1:00 2:00 4:00 24 to 39.4
    (75 to 103) Recirculate and filter at startup.4 No agitation.
    Remaining steps can be done in room light.
    Color Developer 5:00 6:00 7:00 36.7 to 39.4
    (98 to 103) Recirculate and filter. Nitrogen agitation.3
    Pre-Bleach 2:00 2:00 4:00 2 to 39.4
    (75 to 103) Recirculate and filter at startup.3 No agitation.
    Bleach 6:00 6:00 8:00 33.3 to 39.4
    (92 to 103) Recirculate and filter.
    Air agitation.3
    Fixer 4:00 4:00 6:00 33.3 to 39.4
    (92 to 103) Recirculate and filter.
    Air agitation.3
    Wash5 2:00 2:00 4:00 33.3 to 39.4
    (92 to 103) Air agitation.3
    Wash5 2:00 2:00 4:00 33.3 to 39.4
    (92 to 103) Air agitation.3
    Final Rinse 0:30 1:00 4:00 Ambient No agitation.
    Dry As needed Not above 63 (145) --
     
    Michael Scarpitti, Jul 5, 2004
    #26
  7. Ah, okay, my mistake -- I was forgetting the differences between E-4 and
    E-6 (I did E-4 about 30 years ago, but I've never done E-6). I was
    thinking E-6 used a fogging color developer (like a B&W reversal
    process), but in fact with standard E-6 it's a separate fogging bath to
    ensure the color developer can develop all the silver the first dev
    didn't; only the three-bath version combines reversal and color dev.

    The only advantage I can see to processing in the post-reversal part of
    E-6, instead of C-41, is that the E-6 dyes might be a better match for
    the original emulsion sensitivity curves -- which would be fine if you
    wanted straight negatives from your E-6 film, but makes little sense if
    you're after the "cross processed" look of slightly shifted color
    balance and altered saturation.

    And of course your method can't be used with a three-bath E-6, only with
    the longer process that doesn't combine steps.

    --
    I may be a scwewy wabbit, but I'm not going to Alcatwaz!
    -- E. J. Fudd, 1954

    Donald Qualls, aka The Silent Observer
    Lathe Building Pages http://silent1.home.netcom.com/HomebuiltLathe.htm
    Speedway 7x12 Lathe Pages http://silent1.home.netcom.com/my7x12.htm

    Opinions expressed are my own -- take them for what they're worth
    and don't expect them to be perfect.
     
    Donald Qualls, Jul 5, 2004
    #27
  8. But the main thing is that the color masking is absent. It should
    provide a better result than C41. Why doesn't someone compare the two?
    And indeed, E-4 DID have a fogging color developer. I used to run some
    E-4 myself.
     
    Michael Scarpitti, Jul 6, 2004
    #28
  9. Beat me to it. Right on the money.

    Robert Vervoordt, MFA
     
    Robert Vervoordt, Jul 14, 2004
    #29
  10. Yes, your correction is,... correct.

    Yet, something is being missed in this discussion.

    The E6 films will have a Yellow filter layer between the first and
    lower layers. This is made of finely deposited silver and its purpose
    is to remove Blue light from reaching the lower layers, which have
    some Blue sensitivity. In E6 first development this layer is removed
    by a Silver solvent similar to Thiocyanate. This is not present in
    C41 developer or E6 color developer. Therefore, the resulting image
    will have this silver layer, which may not show up as Yellow in all
    cases. Its color may be affected by the subsequent C41 baths,
    resulting in Gray or Blueish base tints and a slight increse in base
    density. This might be dependent on the original emulsion used in the
    camera.

    One other minor point, the composition of the E6 first developer would
    generate some the dye image if there were as little Sulfite as in C41.
    I did this at least once in compounding a B&W developer for C41 speed
    boosting and messed up an E6 roll that I put through the process to
    see what would happen.

    If you were to add Sulfite to a C41 developer and use it for any color
    emulsion as the only developer, you will get almost no color. About
    40 grams will leave the film blank,

    My suggestion is to add some Silver halide solvent, at around the same
    proportion as in E6 first developer, to the color developer formula
    you are using in order to clear the lower densities of halide.

    There are other considerations that could be affecting the final
    image, but I suspect they are not significant. One such is the Iodide
    restrainer in the E6 first developer, which affects the topmost layers
    more than the lower ones in permitting the action of the Halide
    solvent to be controlled.


    Robert Vervoordt, MFA
     
    Robert Vervoordt, Jul 14, 2004
    #30
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