Uneven development with Jobo. Help!!

[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.