Any tips for using a Jobo CPE-2 processor?

Discussion in 'Darkroom Equipment' started by ben-s, Feb 19, 2007.

  1. ben-s

    ben-s Member

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    I just bought a Jobo CPE-2 on ebay.
    I intend to do C-41 and E-6 in it - I got fed up with trying to keep the temperature stable enough with a bucket of water. The automated agitation won't go amiss either...

    Has anyone got any tips for using it?
    I'll be using Tetenal chemistry, at least to start with.
     
  2. pentaxuser

    pentaxuser Subscriber

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    If you intend to use stop bath for film processing then watch that the tank lid doesn't blow off. I don't understand the physics or is it the chemistry of it but stop forms gas in the tank very quickly. Just watch the rubber lid very carefully and you'll see if it's about to blow. If it is you can release the gas by stopping the processing and lifting the lid and then replacing it.

    Alternatively just use inversion agitation for stop away from the rotary processor, then continue with bleach and fix or blix as per normal.

    I have never found it a problem with printing - presumably as the quantity of stop is small compared to the size of the print tank.

    You might want to experiment with a higher water bath temp to ensure that the dev maintains 38C for the full 3mins 15 secs while rotating. This might mean that dev goes in to the tank at a slightly higher temp as it has been sitting in the water bath then loses heat over the 3 mins 15 secs.

    However if you pre soak the film with water at 38C so the tank and film are at 38C then the fall in temp of the dev over 3 mins 15 secs while in the tank and just sitting just over the water bath should be very slight.

    I don't think I'd ever have attempted C41 without a Jobo. Incidentally all my experience relates to C41 only. As you have had success without the Jobo then you should find the change to a Jobo makes processing life a lot easier and more consistent. A dawdle by comparison to non Jobo processing

    pentaxuser
     
  3. cybister

    cybister Member

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    Add a mini-pump for small aquariums for circulation. Temperature will be much more stable.

    Michael
     
  4. MikeK

    MikeK Member

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    Also helps with the draining - better that lifting it up and dumping out the water and risk sloshing it all over the place :smile:

    Mike
     
  5. ben-s

    ben-s Member

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    Thanks for the suggestion about the pump.
    As it happens, I already have one in one of my parts boxes.
    I'll wire it into the Jobo's innards with a waterproof gland - should be neater and safer than having a seperate trailing wire.

    Pentaxuser - thanks for the warning about exploding tanks! I think I'll run short baths off the processor anyway - I think it would be too much faffing to unmount, uncap, empty, fill, cap, mount and repeat in about 30 seconds.

    Can anyone tell me how big the thing is? The only dimensions I have found are the ones for the CPE-2 plus, at 12x16". I'm particularly interested in the height (it has no lift fitted)
     
  6. pentaxuser

    pentaxuser Subscriber

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    Height 9 inches: Width 12 inches: Length 28 inches. By the way, if you have problems with fitting a circulatory pump then all isn't lost. I don't have one and the thermometers at either end of the bath show the same reading to within about 0.1/0.2 degrees C.

    pentaxuser
     
  7. ben-s

    ben-s Member

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    Thanks.
    Should fit nicely where I intended it to go :smile:
     
  8. Flotsam

    Flotsam Member

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  9. Flotsam

    Flotsam Member

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    Also, some E-6 processing steps were designed to be done without agitation. Follow any special instructions and recommendations for rotary processing E-6 from the Chem manufacturer or Jobo.
     
  10. ben-s

    ben-s Member

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    Thanks. I've just had a look at my Tetenal E-6 3 bath instructions, and I can't see anything in there. Maybe this relates to the "proper" 6 bath soup?
    I'll have a look when the manual arrives.
    I was given the 3-bath 5 litre kit when one of the darkrooms at work closed, and I'm very slowly working my way down it.
    I intend to try the full process at some point, if I can get hold of the apropriate chemistry.