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Thread: Jobo Expert?

  1. #1
    A.K.A Lucky Bloke ;-)
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    Jobo Expert?

    I never liked the design of the Jobo expert tank system and after a test my biggest fear was confirmed. The test was simple, 300ml of pyrocat-hd and one sheet of 4x5 using a 3010 tank. The densities are different in both ends of the negative.

    I'm sure that with non-staining and/or a larger volume of developer the results are not that obvious but the problem is still there.

    Any comments?

  2. #2

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    Re: Jobo Expert?

    Use more solution.

    If you really want it to not work, use 10 sheets of film and 50 ml of pyro.

  3. #3
    A.K.A Lucky Bloke ;-)
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    Re: Jobo Expert?

    If I read the instructions correctly the minimun solution for the 3010 is 210ml, right?

  4. #4
    Lachlan 717
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    Re: Jobo Expert?

    Why not try the same test with 500ml of Pyro?

    If it works, you've only used an extra 2ml of Part A and Part B, so where's the issue?

    Have you done the same test with other [non-Expert] Jobo tanks?
    Lachlan.

    You miss 100% of the shots you never take. -- Wayne Gretzky

  5. #5
    Lachlan 717
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    Re: Jobo Expert?

    By the way, what was the difference in density? You didn't mention the specifics, nor how you measured them. Is it a large difference numerically?
    Lachlan.

    You miss 100% of the shots you never take. -- Wayne Gretzky

  6. #6

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    Re: Jobo Expert?

    210mm is the absolute minimum amount required assuming the Jobo is perfectly level. Even then, I would be suspicious. I agree with Lachlan. Trying to mix too little solution is false economy. Using 500mm the only bad negative I ever got out of my Jobo were my fault--not the machines. True, there were a boat load of those bad negatives, but what can I say?
    Michael W. Graves
    Michael's Pub

    If it ain't broke....don't fix it!

  7. #7
    A.K.A Lucky Bloke ;-)
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    Re: Jobo Expert?

    I never had this issue with the 2500 series (with or without reels).

    The point is not the extra amount of developer, is the impact in the development. If the minimum amount needed for a adequate flow inside each chamber is 500ml then there is something missing in the original specifications of the tank.

    I’m using pyrocat-hd staining (and the exhaustion/oxidation) in this particular case as an indicator, as a revealing tool. I’m sure the impact extends to other developers like xtol (resolving power) and E-6 (color accuracy).

    I’ll try to develop some strips with different volumes and get some numbers with the densitometer.

  8. #8

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    Re: Jobo Expert?

    Quote Originally Posted by onnect17 View Post
    I never had this issue with the 2500 series (with or without reels).

    The point is not the extra amount of developer, is the impact in the development. If the minimum amount needed for a adequate flow inside each chamber is 500ml then there is something missing in the original specifications of the tank.

    I’m using pyrocat-hd staining (and the exhaustion/oxidation) in this particular case as an indicator, as a revealing tool. I’m sure the impact extends to other developers like xtol (resolving power) and E-6 (color accuracy).

    I’ll try to develop some strips with different volumes and get some numbers with the densitometer.
    500ml in each chamber? NO. That wouldn't fit in the tank and your motor would burn up. where'd you come up with that?
    500ml total.
    I've never had an issue with even development even with 250ml of c41, e6 or b+w using tmax developer. I'm also not using a densitometer, I'm printing the negs, drum scanning the color film.

  9. #9

    Re: Jobo Expert?

    Quote Originally Posted by onnect17 View Post
    I never liked the design of the Jobo expert tank system and after a test my biggest fear was confirmed. The test was simple, 300ml of pyrocat-hd and one sheet of 4x5 using a 3010 tank. The densities are different in both ends of the negative.

    I'm sure that with non-staining and/or a larger volume of developer the results are not that obvious but the problem is still there.

    Any comments?
    It sounds like you didn't have the tank level on the processor. Next time place a torpedo level on top of the drum and use the leveling wedges to bring it level. Having it level front to back is critical.

    Thomas

  10. #10

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    Re: Jobo Expert?

    Quote Originally Posted by onnect17 View Post
    If I read the instructions correctly the minimun solution for the 3010 is 210ml, right?
    You should know better than to follow instructions. Do you believe the manufacturers in their ISO ratings? I use the same amount of solution - the max in the drum for anything I do. About 1200-1300ml's total solution. Don't starve that film. You want the time to be the determining factor, not the developer exhaustion....

    Lenny
    EigerStudios
    Museum Quality Drum Scanning and Printing

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