Jobo Expert?

[onnect17]

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?

[jeroldharter]

Use more solution.

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

[onnect17]

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

[Lachlan 717]

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 717]

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?

[Michael Graves]

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?

[onnect17]

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.

[vinny]

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.

[tgtaylor]

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

[Lenny Eiger]

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

[Luke79]

I made my First Development in the 3010 yesterday, with efke25 and rodinal 1+49 8min, everything went well and even negatives

[photobymike]

Seriously? LOL LOL Best tanks in the world.... wish they were still being made......

[koh303]

Jobo tanks are still being made.
Not cheap - but are out there and can be bought NEW.

[venchka]

700ml of Xtol 1:3 in a 3010 for all the B&W film I shoot. I never level the tank on my Uniroller base as the tank tends to walk off. I always have the lid end high with the lid bearing on the rollers.

Wayne

[Eric Biggerstaff]

I do the same as Wayne and never have problem, I even use it for 5x7.

[Jim Cole]

I use the 3005 and 3010 tanks and after discovering what you did, I started using a minimum of 600-700 ml of developer and have had beautiful results ever since.

Looks to be the consensus here.

[onnect17]

I use the 3005 and 3010 tanks and after discovering what you did, I started using a minimum of 600-700 ml of developer and have had beautiful results ever since.

Looks to be the consensus here.

Jim,
I'm guessing all most of the jobo expert users here are relying on visual evaluation. I did a test using plus-x and t-max developer with 300ml, 500ml and 700ml. In all the cases I found variations of density in all axis (depth, radius and rotation, invisible to the naked eye) and it's worst than expected (9 locations per sheet, half inch from the border). I'll post the delta-density numbers later.

[Greg Blank]

Make sure you qualify your results using a real name and contact info.

[Fred L]

This is very interesting as I have similar experiences to the others who've had no problems with their 3010 drums. I usually run close to a litre for a full load. Minimum I've used was around 500 ml.

Just asking but is this data from an unexposed neg ?

[Greg Blank]

The ironic thing is these drums have been around for twenty plus years, used by folks like John Sexton etc and claimed to be virtually the best way for home darkroom users to achieve flawless processing results. I have used the drums for about that long and done thousands of negatives, hundreds of tests and the issues are traceble to user error. In my book, soon to be written ;) Its the claiments responsibilty to document the issue in such a way that it can be repeated consistently. That said the drums may not be the method of choice for all developers and circumstances....so qualification is really a requirement- at least in my book to be taken seriously.

[eman]

Dude,--> 72327

Here is a mono and bi-directional density comparison of an image of grey tone, created by my Agfa Alto film recorder. Marked are the spots I read w/my densitometer, (till I sold it here on LFPF) and you can see, except where I TR'ed the readings at the top, there is not enough variation in the density to say so.
72328
I processed 2 sheets separately in a 3010 on a CPP2, one with mono and the other w/bi-directional agitation and took the readings from those. This test was actually just to verify that mono and bi directional agitation produce the same results basically.


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?

[ic-racer]

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?

You just demonstrated that under those conditions 300ml is not enough developer. Two things that people tend to skimp: exposure and developer volume :)

[eman]

Here is a scan of the Jobo capacities for their expert drums.72332
I process in pyrocat, mostly rolls though, in my jobo and somewhat exceed those recs in the 1500 series drums. Most recently I ran a large number of 8x10 sheets in my 3005 for a client and once they were in his hands he sent an email saying "I spent the afternoon in the darkroom yesterday and the negs are printing up beautifully! Good call on all the times, thanks a bunch"
I use a slow rotation and in the case of these 8x10's, to lessen wear and tear on the old gal, I ran them mono-directionally. In the case of the 8x10's I don't think I exceeded the volume recs by much if at all.

[Greg Blank]

I dare say that peoples exposing light sources are the single biggest variable. Objectively looking at it; its unlikely that the enlarger,sun, photo floods or any other light source will not produce some variance that will be deemed of no consequence by the uninformed. The halogen light sources of enlargers can vary by ten lux or more from center to edge- same with regard to the sun, photo floods and strobes.

[mandoman7]

Aside from the question of uneven development, which is generally held to be more true for tank and tray development than drums, the use of 300ml of pyro introduces a possibility of developer exhaustion from what I've read (not tested). This would be exacerbated if the drum was not level, and there was a thin amount of solution on the film.

[Kimberly Anderson]

Thank you for the mono and bi-directional rotation test and densitometry readings. Very interesting. If I read your data correctly I am seeing roughly a .20 increase in density regardless of the sampling location from the mono-directional processsing. This validates what I have been seeing with my own processing even though I haven't been doing any scientific readings.

Very nice.

[SamReeves]

I use the 3005 and 3010 tanks and after discovering what you did, I started using a minimum of 600-700 ml of developer and have had beautiful results ever since.

Looks to be the consensus here.

This is what I've been up to myself. It kinda sucks, but better safe than sorry. And I have the sucker perfectly level, but it does require more chemistry than Jobo advertises. The best thing you can do is grab some old film, and test the chemistry levels until you see no defects.

[Lachlan 717]

This is what I've been up to myself. It kinda sucks, but better safe than sorry. And I have the sucker perfectly level, but it does require more chemistry than Jobo advertises. The best thing you can do is grab some old film, and test the chemistry levels until you see no defects.

From 300ml to 600ml using Pyrocat-HD is using 3ml extra of A and B. As I wrote earlier, a trivial amount.

Why take the time to test minimum volumes when you know that this will do the job? In my opinion, a priggish, needless exercise.

[eman]

I've never come up short in developer volume resulting in unevenness whether running at the Jobo rec. levels or higher. For pyrocat I use more but it's also the math involved. Sometimes it's easier to just make it 100ml greater than Jobo said.... or now 'says' since they are making processors again. Best to keep me and math as far apart as possible as I'm terrible at it so I go with what's easiest to figure out for the total volume and doesn't leave me with a total of 183mls or the like.
Anywho, even times where I've forgotten the pre-wet step I've had 'perfect' negs. They were certainly even anyway.

Ya, math and typing, I suck at that!

[Greg Blank]

Ugh, we cave people never use the 3 R's ;) We just develop photo'd films, in our holes, in the far end of east bund *F*.

[koh303]

what are the 3 R's?