Uneven development with Jobo. Help!!

[RPippin]

So I'm a bit baffled by this recent occurrence. Did a big shoot a couple of weekends ago, around 10 sheets of 8X10 and 20 sheets of 4X5. I started developing them in my usual manner with PMK Pyro in a Jobo. I have both drums, one for 5 sheets of 8X10 and the one for 10 sheets of 4X5. I've been getting pretty consistent results with them for the past couple of years, but this time, probably because of the importance of the project, most of them are crap. There is evidence of uneven development on some negatives, like no developer got the bottom of the tubes, streaks in some and a couple of 4X5's were blank. I know I could have a couple of things going on, definitely a Zebra in the works, but when I shot some 8X10's today and processed them with BTZS tubes, perfect! I have more 4X5's to develop and will use BTZS tubes for them to confirm my theory. So, how finicky really are these damn Jobo's? Should they be perfectly level? I use a drum roller, a bit worn out, and switch directions at even intervals. I use 500ml of chemistry, which should be more than enough. The only difference I can tell from last time is that I placed the roller on a different base in the sink. Should it have some grade to it? It appears that the chemicals don't get sloshed all the way in and out of the tubes. Nothing that drastic has changed in my method, or at least that's what I think. Thanks in advance for any advice I can get. If I can't resolve this, I'll go back to BTZS and you might find a couple of Jobo's on the For Sale list.

[Peter De Smidt]

The drum needs to be level. Perfectly level, no, but pretty level. For 8x10 film in an expert drum on with a CPP2, I always use 1 liter of developer.

[vinny]

Blank negs sounds like another issue no related to jobo drums.
I use 1L of PMK in expert drums split into two batches, 500ml for the first half of developement, 500ml for the second half because pmk is said exhaust when using rotary development. I get better results with this method.
No problems using a cpp2.
I presoak all films.
My machine is level.

[Vaughn]

The drum roller I use (Unicolor) was set up for alternating the direction of the drum -- but because the 3005 drum has a large diameter, there was barely a full turn (if that) before it reversed. So I disconnected it and flip the drum over about every 30 seconds or so. I also use about a liter of developer at a time in the 3005.

[vinny]

FYI, expert drums do NOT need to rotate in both directions to achieve proper development.

[koh303]

This sounds like insufficient liquid amount in the tank, or exhausted/contaminated developer.

[RPippin]

Thanks guys. Vinny, I use the split developer method as well, with the first 500ml for half the time and the second for the other half. My drum is fairly level. I usually sit the Unicolor on a tray turned upside down in my darkroom sink. It does rotate one direction and then reverse to the other direction, and I too have noticed the drum is to large to give a complete rotation so I switch over every two minutes of development time. The developer is fine, it worked beautifully on the four sheets of 8X10 I did in the BTZS tubes. The damn thing is just too finicky for my taste, so if I have to go back to the BTZS method for all but my 5X7 stuff I will, it's only 4 sheets of 4X5 shy and one sheet of 8X10. If I have to constantly watch the drum so that it tracks and doesn't come off the Unicolor, I don't know what the advantage of the Jobo is. Anymore thoughts? I might try disconnecting the direction thingy, Vaughn and see what happens. Thanks all.

[DannL]

I too "had" drums that were too large for the Unirollers. Having a spare uniroller, I opened the bottom and disabled the switch so it would no longer switch directions. I was able to use the 11x14 drums and even the Jobo drum for 20x24. After about 15 seconds in one direction I would lift the drum and swap it end for end. It worked very well. Try rolling the large drum back and forth on a counter top, table, or floor the next time you develop. Place a piece of tape on the drum as a visible reference point to insure you are rolling it a complete revolution or more. If all is well, I would suspect the Uniroller.

I would not exclude the design of the JOBO expert drum either. Using it with the Uniroller might be the overall problem.

[koh303]

http://images.cdn.bigcartel.com/bigcartel/product_images/132968913/max_h-1000+max_w-1000/IMG_9299.JPG
...

[RPippin]

Koh, got one of these too. Will try it out next time. And I'll disable the direction switch as well.

[Sirius Glass]

This sounds like insufficient liquid amount in the tank, or exhausted/contaminated developer.

Also the tank or drum must be level. That means all drums and tanks including Jobo and BTZS. If your setup is not level for Jobo then it will not be level or BTZS. Jobo drums are not finicky. Like all equipment they must be used correctly.

[bob carnie]

plus one.. I split pmk into two developers and use 1liter pre stage total 2 liters pmk for both 8x10 and 4 x5 expert tanks

Unlike Vinny I do both directions and if I know that I have a lot of nuetral grey areas I will manually invert and rotate the first 15 seconds of development and
then put it on the jobo.


This sounds like insufficient liquid amount in the tank, or exhausted/contaminated developer.

[RPippin]

OK, so I seem to have a Zebra again. I hear hoof beats and am convinced it's horses...I developed the last 6 sheets of 4X5 in the BTZS tubes and every sheet had the same anomaly in that there is a half moon, over exposed crescent at the bottom of the sheet (the top, where the dark slide baffle is) that would indicate a light leak. More info...the film was loaded in the holders anywhere from 6 weeks ago to 6 months ago, which is to say I loaded film holders and let them sit for long periods of time before shooting. However, they are all stored in black Calumet sheet film foam lined and sealed (I have black ones for unexposed and the red ones for exposed), in a weather proof tub, covered with a dark cloth and stored under a shelf in my studio. That being said, I've so far eliminated the chemistry as the problem, the rotary processor as the problem, and all that's left is the film, film holders and camera's. Every sheet shot with my Sinar Alpina had this problem, the few sheets shot with my Chamonix out in the field, same batch of film from the same group of holders did not have this problem. I've used this particular Sinar many times in the past, both in a studio setting as well as out in the field and never had this issue. F*cking Zebras!

[Jim Noel]

Your last post indicates strongly that you have a light leak somewhere in the Alpina. Check everywhere, not just the bellows. it could be around the lens mounting or the lens board, as well as in the bellows. Years ago I had a tiny leak around the lens mount which acted like a pinhole and made a secondary image on the film. Anything is possible.

[Patrick13]

Or you maybe have a sometimes-habit of handling your film holders with a finger pressing down on the dark slide at that spot, which will let light in at that edge?

[macandal]

I hope you don't mind my asking this question here, but are these Jobo systems (like the CPP2) the only ones available in the market? Does any other system similar to the Jobos exists or not?

(I've been thinking about getting a CPP2 for 4x5 [mainly].)

Thank you.

[StoneNYC]

I hope you don't mind my asking this question here, but are these Jobo systems (like the CPP2) the only ones available in the market? Does any other system similar to the Jobos exists or not?

(I've been thinking about getting a CPP2 for 4x5 [mainly].)

Thank you.

Jobo is the best out there, unless you want to get a commercial grade setup for $10,000 or something.

The CPP2 and 3010 tank for 4x5 will be just fine.

[bob carnie]

Actually there is no commercial grade setup better than the Jobo or for that matter a stainless steel tank setup. Refrema is the best large commercial processor and the film coming off a jobo is just as good in fact cleaner if you are using one shot.


Jobo is the best out there, unless you want to get a commercial grade setup for $10,000 or something.

The CPP2 and 3010 tank for 4x5 will be just fine.