Jobo film processing problems

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Has anyone experienced "road ruts" on their 120 film processed in Jobo CPP2 or ATL machines? With film that has lots of clear sky or solid values, there is a strip of plus density that runs about one-quarter way in from the left and right sides of the negative (if the roll is held vertically).

If so, I'd like to hear of any solutions.

-- Allen Birnbach (allenb@indra.com), September 07, 2000

Answers

Allen,

You don't say what film/developer combination you are using, or what developer time. These could be critical to isolating the problem. If you are using short developing times (less than 5 minutes) the problem could be that this if where the developer first hits the film. The short times do not allow the other densities to catch up.

Is it possible that this is a light leak problem on your camera or tank?

-- Ed Farmer (photography2k@hotmail.com), September 07, 2000.


The problem occurs with both TMX and TMY 120, developed in D:76 1:1. Times are 7-11 minutes, and happens with three different tanks and assorted (9) reels. This, unfortunately, is plus density, not a light leak, and something Jobo is aware of. Right now, they do not have a solution, although we are trying a few things.

I was looking for anyone else who has had this problem to see how they might have solved it.

-- Allen Birnbach (allenb@indra.com), September 07, 2000.


Greetings,

I've been using a JOBO for a few years now without any of the problems you describe, though I don't use those Kodak emulsions. Some suggestions (perhaps these were offered by JOBO's staff) are: pre-wet your film for 5 minutes, make sure you are using enough chemistry per square inch of film, make sure the processor is level and make sure the chemistry is being poured in fairly quickly. Let us know if you find out what's causing the problem.

regards,

-- Pete Caluori (pcaluori@hotmail.com), September 07, 2000.


Pete, Alas, these are all things I do on a routine basis. The tech rep at Jobo thought there was a possibility the reels were contaminated and is sending a new one to test. Because I am very careful in the darkroom, I doubt that that is the problem, but one step at a time, I suppose.

-- Allen Birnbach (allenb@indra.com), September 08, 2000.

Allen,

Why do you rule out a light leak? This would also show up as plus density. How much added density would depend on the severity of the light leak.

But, I do have a few more questions: Does the are of added density only show up at one location on the film? The next time you process a roll, remove it from the reel very slowly. Note where each problem area is in relation to the reel. Do the problems overlap each time around the reel? Are they staggered around the reel? Do they show up on 35mm film? Can you process a test roll in a small tank with hand agitation?

This problem is very solvable. You need to test each variable before assuming that it is not the problem.

Let us know what you find.

-- Ed Farmer (photography2k@hotmail.com), September 08, 2000.



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