I've used my Jobo CPE2 with the 2509n reels and 2521 tank for years, since shortly after I got into large format and decided that deep tanks just used too darned much solution and made temperature control too hard. I've always had great results from this combination.
Since getting back into photography I bought some more reels and the 2553 tank so I could run 12 sheets at a time, but hadn't done so until this past weekend.
Disaster. First, all the sheets on the bottom reel were ruined, but at least I know generally why. I was shocked when I took them out of the tank because they hadn't even cleared for the middle half or so of the sheets, in spite of 5 minutes in Rapid Fixer. Ok, not enough solution. They developed only some light streaks to the sides. I carefully leveled the processor the best I could - my spirit level bubble may have been touching the line on one side or the other but definitely between the lines, as level as I've ever been able to manage or needed, and the tank calls for 560ml of solution. I used 600 as a convenient number that also fit in the "500ml" bottles when nearly topped off. So that wasn't enough - I need more, and maybe better leveling; I get that. It recommends 640 ml for roll film reels. I'll do some more experimenting but probably if I got to 700ml or so that should be fine on that score. I mention this in case anyone has any experience or input with this particular problem.
The worse problem, because I don't know why it happened or how to fix it, was with the sheets in the top reel, which did process, seemingly normally. But when I looked at the dry film on a light box severe edge streaking is evident. One of them has an odd rectangular pattern of unevenness. Now someone may say to get Expert drums and, if I want to keep the temperature control and automatic rotation, a larger processor, and the thought has occurred to me. But I've processed maybe a couple of hundred or so sheets in a single reel in the 2521 and never seen this problem!
Two things occur to me. One, that maybe since I need more solution for the lower reel, which is on the far end from the lift, I barely had enough solution to cover these and that lead to this. The other has to do with rotation speed. When I got the processor, which is an older one with two speeds, I used the slow speed for film just as recommended. For years I didn't have problems with this. Then I read that Jobo later found some unevenness with this and recommended the fast speed for both film and paper and in fact eliminated the slow speed from later models. I did find some (far more minor than this) unevenness in sky areas on a very few shots on 120 roll film which lead me to adapt that fast speed in the past year or so. Never any problem with roll film. To be perfectly honest, I'm not sure I've run any sheet film since I made the change, though. So all those 4x5 negatives I have from past years that were developed in the Jobo and look just fine, as far as processing goes at any rate, were done at the slow rotation speed. For this run this past weekend I used the fast speed.
The only things different are the two reels in the 2553 versus one in the 2521 and the faster rotation speed.
Here are some examples. See the edge unevenness in the lake scenes and the weird rectangular pattern plus the edge unevenness in the lighthouse. The lighthouse also has some dust ruining it, and I know I ran the lens out of coverage. I'm asking about problems I don't understand or know how to fix myself. This was all the TMY-2 I have exposed right now, but I have a run of Fomapan 400 to process and I'm reluctant to do it until I figure this out. (Though I only have four or five sheets, not sure, so I can run it in the 2521.)
If I have to just limit myself to six sheet runs, that's workable. I have several 2521 tanks and 2509n reels so at least I can run another batch without drying the previous. But I'd rather get the 2553 working. If I can get some ideas beyond using more solution (or some suggestion that this will fix both problems) I'll fire off some test shots and run a test batch and see how it does.
These are just quick scans on my Epson 3200, with no real attempt to get them straight and pretty much less final, just to show the problems.
Any help or insight appreciated.
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