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  1. #11

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    To repeat myself, I use the Fujihunt kit one-shot in the Jobo, which is how the Jobo is designed to be used. In terms of quantity I make a generous hunch as to how much solution to use, not extrapolated from the Fujihunt documentation which doesn't address Jobo use. Fuji / Kodak / Agfa C-41 solutions should be functionally equivalent.

    Tom

  2. #12

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    Just to re-iterate what Tom and the other's have said, Jobo's quantities are designed to provide enough chems to develop film. So when the 1500 tank for a CPE2 says 140mls then you can take it that 140mls is enough to do the film using rotation. Jobo cannot and will not presume to say how many films the same 140mls will do. That's for the chemical manufacturer to say. Most C41 chems will do several films and usually there is a time extension to be applied after film 1 or 2. I only have experience of 1500 tanks on a CPE2 but you can take it from me that for rotary processing 140mls( I usually use 150 as it is easier to measure and "for luck") is enough for a C41 film. I am assuming that the ATL 1500 gives figures for quantities in the same way.

    Provided that you are getting enough films developed in 5L to make the kit value for money then if this is less than might be theoretically developed, I'd be inclined to be cautious about pushing it. No point in accepting lower quality for the sake of saving a few pennies, especially if the film is a one-off and the shots cannot be easily taken again.

    If you really want to see what the limit is, I'd use short clips of film of inconsequential negs and continue using the same chems with time adjustment until the clips fail to meet your standards.

    pentaxuser

  3. #13

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    Quote Originally Posted by pentaxuser View Post
    Provided that you are getting enough films developed in 5L to make the kit value for money then if this is less than might be theoretically developed, I'd be inclined to be cautious about pushing it. No point in accepting lower quality for the sake of saving a few pennies, especially if the film is a one-off and the shots cannot be easily taken again.


    pentaxuser
    I agree. The Fuji C-41 kit is about £30 from Ag Photographic, so assuming 25 or 30 rolls per 5 litre kit, cost per roll is around £1 to £1.20 per roll, which to my "value-o-meter", works out as cheap enough.

    Tom

  4. #14

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    Tom It is even better value in a 1500 tank where even one shot it will do 40 rolls( 2 rolls per reel with 250ml). However reading the OP's posts again I can understand why he asked the questions. From the way he read the instructions it seems he had the impression, as I might have had as well, that the 5L kit was very uneconomical. I think he is U.S based so it might well be more expensive or cheaper than here.

    Hopefully he will have worked out that the ATL -1500 is still quite economical, although it appears that for what I understand to be a more automated process compared to the CPE2, you pay a penalty in volume used.

    At 1.6 rolls per litre of chems, I would give up C41 processing and Mr Fuji-Hunt should give up walking down dark alleys for his own safety :

    pentaxuser

  5. #15

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    Quote Originally Posted by pentaxuser View Post
    Just to re-iterate what Tom and the other's have said, Jobo's quantities are designed to provide enough chems to develop film. So when the 1500 tank for a CPE2 says 140mls then you can take it that 140mls is enough to do the film using rotation.
    pentaxuser
    Jobo never said that 140 ml is for which process (C-41, E-6, Ciba, XTOL or whatever), did it? In fact Jobo also said that the volume printed on the tank is the minimum volume required (to cover the film). That's not saying that much of chemical is potent enough to process the film.

    I understand many have said that they got great results by following these numbers on the tank. My experience from using my ATL-2300 by following the numbers on the tanks were simply not the same. Perhaps I should add. I shot mainly 220 ISO 400 films. They demand more volume of developer. I could not achieve a perfect 220 ISO 400 single roll of negative by processing it with 500 ml of Kodak C-41 developer. But when I did it with 850 ml the result was nearly perfect. Then by checking Kodak's tech pub Z-131 850 ml is marginal still. I had fewer problems in processing 120 negatives. I believe it was due to the fact that I always had 470 ml for my Jobo tank and that volume is potent enough for a roll of 120.

    I am on a quest to find out exactly what the real capacity of Kodak (and Fujihunt) is capable of to achieve the best quality negative, not anything less. I have a serious doubt about those numbers printed on Jobo tanks since it never specify what process the numbers are for. Ever tried the same numbers on E-6? Don't try it. I wasted many precious rolls of Velvia 50 220 rolls before realizing that those numbers were questionable.

  6. #16

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    Quote Originally Posted by pentaxuser View Post
    At 1.6 rolls per litre of chems, I would give up C41 processing and Mr Fuji-Hunt should give up walking down dark alleys for his own safety :

    pentaxuser
    Low volume home processing is never economical to compete with labs down in the street. The reason for home processing is mainly for quality and fun. I purchase Kodak chemicals directly from the warehouse of a wholesale supplier (California). I use C-41B developer replenisher + starter, C-41RA bleach and regular fix. For less than $300 I get plenty of chemicals for my ATL-2300 for 2 - 3 years. I over bought too much. But my cost per roll of processing down to $1 - $2 each based on 4 220 rolls per gallon.

  7. #17
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    The under-lid diagram on the Jobo refers to 35mm, 4x5, and 120 film. Some common sense is required here.

    For a 220 roll I'd double the solution volume per roll, up to the capacity of the drum. You probably can't do more than three 220, or six 120, rolls per large drum in the ATL 1000/1500, because the required minimum chemistry to physically process more than that is a volume that exceeds the tank capacity.

    Frankly, this doesn't seem that hard, or complicated. Guess I'm just a simpleton who's gotten perfect results with hundreds rolls and sheets, in both C-41 and E-6, in 35mm, 120, and 4x5 sizes, for the past four years by stupidly following Jobo's directions. What could they possibly know about those processes, or the machines they built?
    Michael Sebastian
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  8. #18

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    Mike, I have about a dozen of Jobo drums, including 1510, 1520, 1530 and 1540. I also have 25xx drums but I don't use them. I could do one roll of 400VC with 850 ml of developer by using a combination of 1530 and a 1540. I have done it with one 1530 for a single roll of 400VC with 470 ml and the result was simply not on par. It's not a math problem, believe me. The ATL has 1000 ml supply tanks. I can use larger drums but I can have 1000 ml of juice only. That means I can not process two 220 rolls in one process.

    I understand that you have processed hundreds of rolls by following the Jobo numbers. I stopped doing that after a number of ruined rolls. For some reason I do not see perfect negatives that way. Jobo should know that for different processes the volume of chemicals required for different films are different. Why do they provide only one set of volumes for all processes? I can point out flaws in the numbers. They give a same volume for a same drum but different number of rolls of films. See the table you will find that. I don't have it on hand now.

  9. #19
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    Quote Originally Posted by MikeSeb View Post
    Frankly, this doesn't seem that hard, or complicated. Guess I'm just a simpleton who's gotten perfect results with hundreds rolls and sheets, in both C-41 and E-6, in 35mm, 120, and 4x5 sizes, for the past four years by stupidly following Jobo's directions. What could they possibly know about those processes, or the machines they built?
    Mike I totally agree, seems pretty simple to me as well. The tank say to use 240ml or 270ml or whatever, that's what I do and things turn out just fine.

  10. #20

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    My understanding (the one I've been using the last few months as I learn how to do C-41 and E-6 processing at home with a Jobo CPE-2 Plus) is this - the numbers that Jobo publishes are the minimum volumes needed to fully immerse the film contained in the tank / reel combination stated. So, for my 2521 tank, 2509 reel, and one roll of 120 film, 170ml of mixed chemical is required to fully cover the film. For 2 120 rolls, or 1 220 roll, 270ml of chemical is required.

    Now... the second part is the more important - what does the chemical manufacturer tell you is required for a given roll of film? Well, for Kodak, they spell it out explicitly in the z-pubs - in terms of chemical required per square foot of film. I simply rolled out a full length of 120 film one day, measured the square footage, and determined the chemical minimums - using the E-6 kit (only kit available here in the states!), for a 220 roll, I calculated it is about 312.5ml required. For 120 it is close enough to 270ml that I just use that. Note also that the E-6 kit is strictly one-shot - no re-use of chemicals at all.

    I've found that going from that, to a Tetenal C-41 kit (I'd do Kodak or Fuji if a kit was available here tho!), has been much less precise, as Tetenal provide literally the bare minimum of documentation with their kit. (yeah, even the liquid one). So for now, I'm mostly guesstimating what it should be based on my experiences with the Kodak kit, and using those minimums... but I am also reusing the chemistry. I processed three 120 rolls a few weeks ago in about 250ml of chemistry, reused between each run, and all seemed to come out as expected. I'd much rather have the reliability of a Kodak Z-pub to pull a real value from, but for now, this is what I'm able to do.

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