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  1. #11
    Jerry Basierbe's Avatar
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    I've been using Kodak indicator stop at 2% for a few years and haven't seen any problems. I have seperate bottles for color and b&w use.

    Jerry

  2. #12

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    Quote Originally Posted by chorleyjeff View Post
    I have just read again the Fotospeed CKRA4 processing kit instruction, for RA4 paper at 35c. They say for Kodak papers use a 5% solution and 2% for all others except Fuji for which it says use no stop bath ie go straight from developer to blix.
    Question is why no stop for Fuji? I should add that I use Fuji CA without stop bath in a Nova slot processor with no staining problems - I replenish at the same rate as the developer. Also what difference would it make using stop with Fuji CA?
    Cheers
    Jeff
    Jeff. I was doing a search on Fotospeed papers actually when this thread came up. Did you ever get an answer on why no stop with Fuji and Fotospeed RA4

    I have never used Fotospeed RA4 but was considering it and I have Fuji paper for which i have always sued a stop with other RA4 chems such as Tetenal and Paterson. I rotary process and wonder about not using stop because of what PE says and the reduced life of blix without a stop bath?

    If Fuji is OK with stop for other RA4 chems I wonder what makes Fotospeed NOT OK with stop for Fuji RA4 but OK for other chems.

    My reasoning is: If Fuji paper is OK with stop for other RA4 chems then it can't be anything in the Fuji paper. On the other hand if Fotospeed RA4 chems need or at least can use stop with other than Fuji then it can't be the peculiarity of Fotospeed chems. If it was you'd think that Fotospeed would say not to use stop with any paper

    OR is there an explanation that reconciles this? Assuming of course that Fotospeed haven't just got it wrong.

    These days I wonder who the other papers( not Fuji or Kodak) would belong to?

    Thanks

    pentaxuser

  3. #13
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    The use of a stop bath with RA papers is dependant on the pH of the Blix. Since most RA blix baths are about pH 6.5 for stability and activity purposes, a stop is sometimes useful especially with drum processes.

    With a tray process I seldom find a need for a stop.

    PE

  4. #14

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    I do drum processing for RA4 (temperature controlled at 95°), and I find that plain warm water works just as well as a stop bath.

  5. #15
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    For those interested, the color developer is absorbed into the coupler solvent droplets. Incomplete or exhausted blix or incomplete washing will leave some of the CD3 in the droplets which will cause a slightly pink stain that slowly vanishes, or it will slightly degrade the dye stability. This is a tiny change which varies depending on retained CD3.

    The current process, when well run, will remove all of the CD3 without a stop, but a stop is positive assurance that it is all removed if the process is marginal for any reason.

    So, this is another reason why I use a stop.

    I said above that I seldom found a need for a stop with tray processing. This is due to the better agitation and the single sheets. A drum process is less efficient in washing prints. I find that with my drum, I have to use a supplemental wash to remove all residual blix coloration from my prints.

    PE

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