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

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

  1. Nick Zentena

    Nick Zentena Guest

    I know I shouldn't have an orange base but what should the colour
    be? Greyish? Or clear?

    Thanks
    Nick
     
    Nick Zentena, Jul 3, 2004
    #1
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  2. Assuming this is an E-6 film cross processed in C-41, you should have
    the same clear base in unexposed areas that you'd have in fully burned
    out areas (like the 35 mm leader) as a positive transparency. Only B&W
    films have a gray base (which, I'm informed by someone who should know,
    is still a color in the anti-curl back coating or underneath the
    emulsion, not in the plastic material of the film base itself).
    Overall, though, base color is determined by the film type, not by the
    process.

    --
    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 3, 2004
    #2
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  3. Nick Zentena

    mr. chip Guest

    Well all of mine have come out with a yellowish base. Maybe with a hint of
    brown.
    Have you tried cross-processing that Astia yet?

    Simon.
     
    mr. chip, Jul 3, 2004
    #3
  4. Nick Zentena

    Hemi4268 Guest

    The very end of the leader is bluish and I guess the
    Yes, you might get some sort of tint if you don't use a stop bath between the
    dev and bleach. Normal C-41 doesn't call for this but several Kodak pubs
    indicate a tinted base might happen without the stop on print film. That most
    likely goes for chrome film processed in C-41 also.

    Larry
     
    Hemi4268, Jul 3, 2004
    #4
  5. Nick Zentena

    Nick Zentena Guest


    Ya this morning. The film is drying. It's fairly clear but if you put a
    gun to my head I'd call it grey. It's not like frosted glass but it's not
    perfectly clear either. The very end of the leader is bluish and I guess the
    grey really has a mild blue tint to it.

    Nick
     
    Nick Zentena, Jul 3, 2004
    #5
  6. Nick Zentena

    Nick Zentena Guest


    I was expecting perfectly clear base but it's not. The negatives seem good
    will see how they print.

    Nick
     
    Nick Zentena, Jul 3, 2004
    #6
  7. Nick Zentena

    mr. chip Guest

    Hmm... this is interesting. I use a stop bath.
    I also use a pre-wash of warm water to get the film up to the right C-41
    temperature. When I pour the pre-wash away it's VERY blue... (I'm talking
    about cross-processing Astia here).

    Simon.
     
    mr. chip, Jul 3, 2004
    #7
  8. Nick Zentena

    Nick Zentena Guest

    I didn't do a pre-wash. The exposed leader is deeply blue. Kind of nice in
    a way. Without the orange mask I'm not sure how to judge the negative
    colours but if it wasn't cross processed they'd look right.

    With me the film is putting out enough dye to make the stop change
    colour. So not only does it turn the developer but the stop is orange also.
    It's mostly C-41 film in the tank.

    Nick
     
    Nick Zentena, Jul 3, 2004
    #8
  9. It would make more sense if you process yourself to use E-6 color
    developer and simply skip the first developer and reversal bath steps.
    After all, E-6 color developer is going to be more suited to E-6
    films.
     
    Michael Scarpitti, Jul 3, 2004
    #9
  10. The gray in 35mm film is NOT an anti halation coating.
    Rather it is a pigment in the support itself. Both back
    coating and under emulsion coatings are used for
    anti-halation purposes, the latter in most color films.
    These are decolorized by the sulfite in either developer or
    fixing bath. No color film uses a back coating other than
    the Rem-Jet coating used on Kodachrome and some older motion
    picture stocks.
    You can prove this easily by soaking some film in
    household bleach. This will completely remove all the
    gelatin from both sides of the film leaving only the
    support.
    The orange color in color negative film is not the
    support or a coating but rather the color couplers (dye
    formers). They are colored when in the unreacted state to
    provide an automatic color mask to correct the parasitic
    transmission of the dye. In effect they raise the minimum
    density. Usually, colored couplers exist in two layers of
    the emulsion. The coupler in image areas is converted to the
    appropriate color for that layer. A careful examination of
    the image under high magnification will show that the "base
    color" does not exist in highly colored portions of the
    image. The idea of using colored couplers for masking
    originated with Westly T. Hanson of the Kodak Research
    Laboratory sometime in the mid 1940's. Kodak's first
    chromogenic negative film, Kodacolor, did not have the
    couplers, it was introduced in a later version of Kodacolor
    and in Ektacolor.
    There is no way of removing the mask without also
    removing the dye image.
    This method of masking is never used on color reversal
    films, nor is anti-light-piping pigment in the support. All
    should have perfectly clear supports after processing.
     
    Richard Knoppow, Jul 4, 2004
    #10
  11. Nick Zentena

    Hemi4268 Guest

    It would make more sense if you process yourself to use E-6 color
    I don't think this will work. The color developer I think is a fog type
    developer. Everything will have a fog if it works at all.

    Larry
     
    Hemi4268, Jul 4, 2004
    #11
  12. Define "cross processed." If you processed the film in B&W chemistry,
    you won't have bleached away the colloidal silver yellow filter layer
    (which normally protects the green- and red-sensitive layers from blue
    light exposure in the camera). If you processed in C-41, the bleach-fix
    or bleach step that removes the image silver should have also removed
    that filter layer.

    So, what color did you wind up with? C-41 films, of course, have the
    orange base, but that's the base color (i.e. it's under the emulsion and
    antihalation, or in the back coating, and designed not to wash out);
    slide films generally have a fully clear base.

    --
    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 4, 2004
    #12
  13. You and Rowland Mowrey need to compare notes, so we can all get the same
    story. I just had it from Mowrey on photo.net (like literally a few
    days ago) that the gray color of B&W films is in the undercoating or
    back coating, not in the support; he claimed to have handled hundreds of
    samples of support material and all was completely clear.

    The way you tell it is the way I had understood it, too -- but in direct
    opposition to Mowrey's tale, and with his background, I have to give him
    some credibility. Perhaps the support is dyed before coating, but at a
    later stage than where he handled the samples...

    In any case, we all seem in agreement that no E-6 film should have a
    residual pigment, dye, or any other sort of color in areas that were
    either grossly overexposed (for normal reversal positives) or completely
    unexposed (when cross-processed in C-41). I'd be interested in what
    Nick has...

    --
    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 4, 2004
    #13
  14. I think you mean to skip the first dev and *bleach* steps -- if you skip
    both developers, you'll get clear film base after the fix.

    --
    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 4, 2004
    #14

  15. Worse than that I think. It will make all the halide developable so
    the film will come out black. If you bleach out the silver it will
    still be black since all the coupler will have been converted to dye.
    Remember that the dye is produced by a reaction of the coupler with
    developer reaction products.

    Richard Knoppow
    Los Angeles, CA, USA
     
    Richard Knoppow, Jul 4, 2004
    #15
  16. Nick Zentena

    Nick Zentena Guest


    I glanced at a formula for the 1st E-6 developer. It looks like a B&W
    developer.

    Nick
     
    Nick Zentena, Jul 4, 2004
    #16
  17. Nick Zentena

    Nick Zentena Guest


    E-6 film in C-41 chemicals.

    Nick
     
    Nick Zentena, Jul 4, 2004
    #17
  18. Nick Zentena

    Hemi4268 Guest

    I glanced at a formula for the 1st E-6 developer. It looks like a B&W
    CORRECT

    Larry
     
    Hemi4268, Jul 4, 2004
    #18
  19. Nick Zentena

    Nick Zentena Guest


    The negatives are very grainy. Reminds me of 1980's 400 speed film but
    worse. OTOH the prints don't look that grainy. It sort of blends in. By
    chance the colour filtration came in at the intial starting point for the
    paper so I didn't have to waste any time getting that right.

    Nick
     
    Nick Zentena, Jul 4, 2004
    #19
  20. Nick Zentena

    BertS Guest

    No, the orange color is the leftover color couplers (I think they are
    colorless on at least one of the layers) and act as a built in correction
    mask. Where the coupler forms a color there is no masking (for that layer) and
    where there is no color formed the leftover coupler leaves a color residue.

    Bert
     
    BertS, Jul 4, 2004
    #20
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