Agitation and Time effects in Color Developer and Blix Baths

Discussion in 'Color: Film, Paper, and Chemistry' started by pukalo, Sep 12, 2013.

  1. pukalo

    pukalo Member

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    Anyone know what the effect, if any of continuous slow agitation (I use a Peterson tank and use the rotary stick for agitation, not tank inversion) when doing the Color Developer and Blix steps with Tetenal E6 kit?

    How about increased times time in Color Developer or Blix, does this cause significant issues, or is it advantageous as supposedly these are "to completion" chemical reactions?
     
  2. pentaxuser

    pentaxuser Subscriber

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    Here's my thoughts: If the rotary stick works in both directions then it ressembles the clockwise/anticlockwise agitation on a Jobo processor. If the rotational speed is the same or even similar then the film doesn't know that it is being rotated manually so nothing should change compared to Jobo rotary E6 processing.

    I'd stick with whatever Tetenal says for each stage

    pentaxuser
     
  3. Wolfeye

    Wolfeye Subscriber

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    Can't answer the agitation question for sure, but I have read somewhere that continuous slow agitation is good for C-41; in fact it's preferred but nobody wants to stand there and do it for three and a half minutes, hence the 5 sec every thirty minutes recommendation. The development steps are quite time and temperature specific. Don't mess with them. Blix is a lot more forgiving and yes, it's a run-to-completion reaction.
     
  4. Rudeofus

    Rudeofus Subscriber

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    Both CD and BLIX are "run to completion" steps in E6, so time and agitation just has to be sufficient. In CD you have the competition between couplers in the emulsion and competitive couplers in the CD (the Citrazinic Acid, see here), also don't forget the Sulfite which scavenges some of the oxidized CD-3, so you want to stick to the instructions from the kit manufacturer.
     
  5. MartinP

    MartinP Member

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    About the rotation thing, with the stick and on a Jobo (or other rotating tank system). With the hand twister thing, the film does not leave the chemical and the rotation speed near the centre of the spiral is minimal. With a Jobo (or other constant rotation system) the tank is horizontal, not vertical, during rotation and every part of the film leaves the chemical momentarily on every revolution. The two manners of agitating are not comparable at all.

    With a Paterson tank you may have to 'fart' the lid during processing due to the build up of gas pressure, but basically the tanks are designed for inversion and the most even results are achieved like that. I am assuming that you are not using a thirty-five year old Paterson with a screw-fitting top, leaky age-hardened plastic sealing-rings and rather slow fill/empty possibilities. If that is the case, I strongly recommend replacing it with the current version as they don't leak. The reel size is the same.
     
    Last edited by a moderator: Sep 13, 2013
  6. bvy

    bvy Subscriber

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    My own process (C-41) is this: Twirl stick for the initial 30 seconds, since I can't possible get the Paterson lid on that fast. After 30 seconds I put the lid on properly and quickly invert twice every fifteen seconds.

    For the other baths, I only use the stick. This is much less messy and I don't have to fuss with burping the tank and such.