Unevenness with 4x5 in Jobo 2553

[Roger Cole]

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.

[rdenney]

600 ml, even if it covered the film, might not be sufficient to develop all the film before it is exhausted. Kodak suggests that Xtol, for example, can develop 80 square inches of film per liter of solution. You processed 12 sheets, which 240 square inches of film, with half a liter. I'll bet you exhausted your developer.

My Jobo 2551 tank suggests 8 sheets of 4x5 using two 2509 reels. But 8 sheets is 160 square inches, and requires two liters of Xtol working solution. My temptation with that developer (of course, I don't know what developer you were using) would be to fill the tank with a full liter and then develop two sheets per reel.

Pyrocat-HD, which is what I am experimenting with, needs 75ml of 1:1:100 working solution per 4x5 sheet. That means 12 sheets would need 900 ml, minimum. I will use a full liter. If that's what you were using, you still had too much film for the 600ml of developer you used.

With your single-reel, you probably filled it to the brim for upright development, which would provide a much greater amount of solution per sheet.

Rick "who has collected the same basic stuff but not yet used it, though he has films ready to develop" Denney

[Roger Cole]

Well, not exactly. I used two reels but I only had ten sheets total. And due to a screw up on my record keeping (I'm feeling like I'm re-creating all the beginner mistakes again ten years later) two of them were actually unexposed.

And I don't fill the single one to the brim. I use what it says on the side of the tank rounded up. Always done via rotation on the machine. I've never exhausted developer before, and I doubt I did now as the ones on the other real are fully if unevenly developed.

Developer was T-Max RS diluted 1+5.

But thanks very much for the input. It's a good thought, I just don't think it's likely given the 10 sheets, only 8 of which were exposed (and the middle of three didn't get wet anyway) and 100ml of concentrate.

[Roger Cole]

I should say in my defense that the dark slides on the unexposed ones were turned to white - unexposed. But my notepad listed them as exposed by holder number, so I ran them rather than risk double exposure figuring losing the sheets was better than ruining two shots on each.

[Roger Cole]

Update - I had to retrieve my 2521 tank from the darkroom to recall exactly how much solution I use with a single reel and six sheets - it calls for 270 ml so I round up to 300. This works nicely for my 1+5 dilution of T-Max RS, 50ml concentrate plus 250ml water. So I have often developed six sheets in half the solution I used for only 10, two of which weren't exposed and three of which didn't get solution on them. So that's not it.

[koh303]

What Rick says is basically true - the capacity filling amounts on the Jobo tank labels refer to color chemistry, where a much smaller amount per square meter is needed (what the hell is an inch anyways?), and as most of the chemicals are replenisher based, they do not get exhausted so fast.
For 12 sheets in the 2553, you need at least 640ml, just to cover all of them with solution, that does not say how much a BW sheet of film will need when taking in to account the effective chemical capacity per square meter or per sheet.
Jobo actually says (and experience also suggests) that when doing sheet film your CPE2 which has 2 speeds, should be set to the lower speed. The CPE2+ has only one setting which is somewhere in the middle between the two speeds of the CPE2.
The high rotation speed does not allow enough time for solutions to pool or move fast enough to reach each sheet, so the combination of the high speed and small amount of chemistry, i suspect is your problem, As i routinely process 12 sheets of 4X5 using 2553 tanks, with no issues (BW and color).

One thing of note - the max capacity of the rotation motor of the CPE2 is stated by Jobo to be 600ml. Though the motor will spin a tank with 2 liters or more, the strain of anything beyond the recommended max capacity will eventually slow and kill the motor or other relays or components on the board.
So - even though in theory 640ml is fine for c-41\e-6 it might not be enough for whatever BW process you are running, and you might not want to run such a large load on a CPE2.

Even though you ran the same process with the multitank 2 with 300ml, with good results the larger size of the multitank 5 coupled with the higher speed and less then needed chemistry will require to adjust the capacities.

One other thing, Tmax RS, which is a high capacity commercial machine use developer (and replenisher) is less then ideal for Jobo processing, though it works fine in most cases.

In any case i think a good guideline for sheet film will be to start with a minimum of 75\80ml per sheet, with 100ml being a safe margin. Running 8 sheets per tank thus will call for less then 800ml, which is after all not to far from the recommended max capacity of the motor.

Even of the processors itself is 100% leveled, if you are working with a lift (which by the way adds some more strain to the motor, due to the transfer gears friction), the lift arm or lift base might not be 100% when in the lower position. This might also change during a run, as you lift and lower it, and it flexes out of level, not much you can do about that in the CPE2 which flexes alot, other then use a bit more chemistry to compensate, and make sure all film is getting exposed to chemistry.

[Roger Cole]

I am in fact not sure if I have used the faster speed for sheet film before. I only started using it for roll film earlier this year when I saw a few frames or 120 FP4+ with unevenness in the skies. It was slight and might not be noticed by anyone not looking for it, but going to the faster speed seemed to fix it without causing any other issues. I'm not sure if I've run 4x5 since then. No problem to go back to the slow speed. I suspected that anyway.

I'm still not really buying the developer exhaustion considering half as much developer has never given me a problem developing 60% as much film, even counting what wasn't exposed or immersed in chemistry. I've used T-Max RS since the 90s when a friend recommended it for T-grain films. I tried Xtol but didn't like it as much - no huge reason just the powder mix, inconvenient 5L stock size and the fact when it goes bad it doesn't change color. I use D76 for some films (like the Foma.)

I think I'm safe to run my Fomapan now using the 2521 multitank and the 300ml I have been using, on the slow speed. I might up the quantity of solution slightly.

It's rare that I need to run more than six sheets at once but I will try to shoot 12 sheets of Foma (because it's cheap - Arista branded) test exposures and run them all with 700-800ml on slow speed. I'll bet that does it. It won't be a complete test since the film and developer type is different, but it should show any problems with evenness. Thanks for the info on the rotation speeds (I am also using a lift.)

[koh303]

Good luck - please share the results when you have then so we can see if this issue was resolved.

[Kevin J. Kolosky]

"I'm still not really buying the developer exhaustion"

I would tend to agree. If it was developer exhaustion the streaks would more than likely be all over rather than concentrated in certain areas but it appears that you have good development in all of the areas.

So it has to be either uneven development due to chemical flow(surge of some type) or possibly, but remotely, some type of light leak.
Just to rule that out, I would try some film from a different box of film, and then a completely different film holder to rule that remote possibility out. If that doesn't do it I would start with 1 sheet of film with a full drum to see if the film itself is causing some sort of weird chemical flow.

In other words, only change 1 thing at a time. Eventually you will get it.

[Sal Santamaura]

...Kodak suggests that Xtol, for example, can develop 80 square inches of film per liter of solution...

Wrong by an order of magnitude. Kodak data indicate that 100 ml of XTOL stock solution is the minimum necessary to process 80 square inches of film. See the fifth paragraph of the second column on page two here:

http://www.kodak.com/global/en/profe.../j109/j109.pdf

...It's a good thought, I just don't think it's likely given the 10 sheets, only 8 of which were exposed (and the middle of three didn't get wet anyway) and 100ml of concentrate.

Per the first paragraph of the second column on page two here

http://www.kodak.com/global/en/profe...bs/j86/j86.pdf

45 ml of TMAX-RS solution is required for each 80 square inches of film. The 100 ml you used is pretty close to the 112.5 ml that ratio would specify for 200 square inches, so I agree that exhaustion had nothing to do with your bad results. Insufficient coverage as well as reel / rotation speed interactions are likely to blame.

Yes, I'm one of those who will suggest moving to Expert drums. Absolutely uniform negatives every time.