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  1. #11

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    I bought a box of this stuff in 8x10 when it was first released and could never make filters produce any real effect. It always produced a magenta cast - not excessive but annoying. I had a well sorted RA4 processing setup using a roller processor so processing variations were not an issue. In the end I used most of the box for contacts as someone here still does because I thought it was a pretty ordinary B&W paper that was a good idea only in theory. I understand that Kodak, a bit later, released another RA4 chromogenic B&W paper that was better and also one that produced sepia tones. They were only available in rolls and apparently did not last on market very long. OzJohn

  2. #12

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    Mike, Since you said you also had this magenta cast you had not been able to get rid of, do you have a way to try the steps I try at your own scale. Is that possible for you ? I am not a chemist or far from me, but I came up with those steps after imagining a way to reduce developer activity... and it worked. In fact if I kept reducing the temperature and agitation, it starting showing a slight cast in the opposite direction.

    Pentaxuser. the clue that I had was; the publication states:

    "Processing conditions may affect the color (hue) ofPORTRA Black & White Paper. You may see a hue change on the magenta/green axis due to variations in developer tank activity and pH. Low developer activity and/or pH (typicallysevere oxidation and/or under-replenishment) will cause ashift toward a green hue. High developer activity and/or pH(usually over-replenishment) will cause a shift toward a magenta hue."

    Tell me if my reasoning makes sense, or just a very lucky shot...
    thx

  3. #13

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    Yes I think your reasoning makes absolute sense and I noticed the same section in the Kodak publication. What I was trying to say rather clumsily was:1 Kodak doesn't seem to be helpful about what the user does to lower developer activity, given that this magenta cast may be easy to create. You had to discover this yourself and presumably had to deviate from what Kodak would have said was the correct process which should have produced a neutral print

    2. It is still a mystery why at the first time when the issue arose and without your later changes you did manage to get a neutral print alongside your magenta cast prints.

    For what it is worth I once used the Kodak TCN 400 film and had it commercially developed and printed on RA4 paper and there was a slight but noticeable hint of magenta in some prints. I suspect that there was a hint in all the prints but in some scenes and tones it was almost invisible but somehow none of the prints looked right compared to silver gelatin prints.

    It certainly dissuaded me from bothering with Kodak chromogenic films and RA4 paper for B&W prints again.

    pentaxuser

  4. #14
    Mike Wilde's Avatar
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    Aug 2006
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    Could be a while until I get to trying your fix, but I will keep it in mind. I have a fuji roller processor, and was printing ra-4 on old royal paper last postcard exchange. Winding off 30 prints, the last ten came out progressively more magenta/purple, paricularly on some where there was known edge fogging.

    So I peeled the processor cover off to check the dev tank temp, and whoa, the thing was up to 45C.

    Turns out I think I now have a flakey set point potentioneter or intermittent solution temperature thermistor.
    I swapped all of the electrolytic caps out of the control board three years ago, so they should not be a problem again yet.

    So yes, even regular RA-4 can go purple if over developed. I will try a more dilute RA-4 for the portra mono stuff next time I have the zing to use it.
    my real name, imagine that.

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