Help with Kodak Roll and sheet film pinkish coating!!

Discussion in 'Kodak' started by jjs, Feb 6, 2005.

  1. I am not quite sure what you mean by affinity. According to the
    literature Ammonium thiosulfate is less affected by the presense of
    iodide ions from silver iodide than is sodium thiosulfate. Iodide acts
    to slow down fixing. Since most modern films have a large amount of
    iodide in them ammonium thiosulfate has the advantage.
    It takes something like three free thiosulfate ions to complex a
    silver halide ion. The ability of fixing baths to complex silver halide
    to the point where it becomes entirely water soluble is limited. Fixer
    will continue to clear film long after it stops being able to remove
    the partially complexed silver. The use of two successive baths
    increases the capacity of both salts to fix completely. Since most of
    the iodide comes out in the first bath the second one is effective even
    with high iodide emulsions.
    Quite some time ago Micheal Gudzinowicz posted a complete
    explanation of how fixing baths work to this news group. I think it is
    still available via Google.

    Richard Knoppow
    Los Angeles, CA, USA
     
    Richard Knoppow, Mar 7, 2005
    #21
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  2. jjs

    dan.c.quinn Guest

    Affinity - Attraction The ammonium ion has a near
    zero, in chemistry, affinity for silver in the presence of
    iodide. That is, the ammonium ion will complex very nearly not
    at all with silver if iodide is present. It will complex well
    with silver when chloride and less well when bromide
    are present.
    That's true. It ain't Rapid Fixer any more. I'd think
    only a little slower to use S. Thio. fixer. It is the
    thiosulfate ion, with it's great affinity for silver
    in the presence of iodide that does the job.

    That should explain it. That should explain it. Dan
     
    dan.c.quinn, Mar 8, 2005
    #22
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  3. jjs

    Tony Guest

    Getting rid of the pink the Tony way.

    (1) Leave the film in the fixer and make yourself a cup of coffe.

    (2) Drink Coffee, go back and agitate film tank.

    (3) Leave the film in the fixer and make yourself a sandwich.

    (4) Eat sandwich, go back and agitate film tank.

    (5) Leave the film in the fixer and walk the dog.

    (6) Go back, drain the tank and wash the film for about an hour.

    Gauranteed to wor
     
    Tony, Mar 8, 2005
    #23
  4. jjs

    John Guest

    Yeah and guaranteed to eat away at the shadow detail as well.

    2 baths, each for 3 minutes in Kodak Rapid Fixer sans hardener
    and wash for 5 minutes, HCA for 5 minutes, wash for 15 minutes.

    BTW, if the film is fixed properly and the pink stain is still
    present all you really need to do is to lay the negs on a lightbox for
    a while. The dye is UV sensitive and will fade.


    Regards,

    John S. Douglas, Photographer - http://www.puresilver.org
    Please remove the "_" when replying via email
     
    John, Mar 8, 2005
    #24
  5. jjs

    Tony Guest

    OK! So my timings may be a little exaggerated but do check out th
    following link to the yellow giants technical forum.
    Just to clarify, at least doubling the fix time will not eat you
    shadow detail away, in fact if you left it in the fixer all night yo
    would be hard pushed to detect any tonal compression.

    The bit about "UV Sensitive and should fade" is a new one on me.

    So you don't feel a faded stain across your negs will give you
    problem then?

    http://tinyurl.com/4cl9
     
    Tony, Mar 9, 2005
    #25
  6. jjs

    dan.c.quinn Guest

    Give one-shot fix a try. With A. Thio. I use 20ml
    of concentrate in 500ml for 120. Clears nicely my Pan F+
    including the pink. Give a 3 minute agitation then in dim
    light examine. One fix should do as the solution is very
    dilute and the fix fresh to start.

    Unless you are sure of your water supply, use distilled.
    I'm sure certain impurities in water can form insoluble
    compounds with the silver thiosulfate complex which
    can precipitate in the emulsion. Those impurities
    may be the source of some pink woes. Dan
     
    dan.c.quinn, Mar 9, 2005
    #26
  7. jjs

    John Bartley Guest

    For what it's worth, I needed a sheet of 4x5 film cleared. I slipped a
    sheet of unexposed FP4+ into a "brand new" mix of Ilford Rapid Fixer and
    left it there for 30 minutes. The mylar had a pinkish tinge to it even
    after a good washing, and now that the sheet has sat on my desk for
    about two weeks, the pink tinge is fading away.

    cheers

    --
    regards from ::

    John Bartley
    43 Norway Spruce Street
    Stittsville, Ontario
    Canada, K2S1P5

    ( If you slow down it takes longer
    - does that apply to life also?)
     
    John Bartley, Mar 9, 2005
    #27
  8. jjs

    dr bob Guest

    A search for this phenomenon will produce a huge listing of discussion on
    this subject. Through extensive physical tests and observations it has been
    proven that the color retention is the result of a sensitizing dye in the
    emulsion. It will come out completely on thorough washing and quicker with
    HCA or equivalent. Even if it remains it will have minimal effect on
    printing. My sheet films clear much faster than 120 roll film for some
    reason - but they all clear if soaked in successive quiescent water baths.
    The color will look differently depending on the type of film and the
    manufacturer.

    Truly. dr bob.
     
    dr bob, Mar 11, 2005
    #28
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