Another uneven development with Pyro HD two bath with Jobo 2850

[Hugo Zhang]

I developed a sheet of 16x20 hp5 film with Jobo tank 2850 print tank using Pyro HD two bath. I prosoaked for five minutes and followed everything according to instructions I have read here. There is a two inch wide band running half way through the sheet. Almost like and light and shade on the negative. I had a similar case with one sheet of 8x10 film with my Jobo 3005 tank three days ago.

Anybody has similar experiences? I have heard that Pyro developer sometimes give uneven development, especially on ULF sheets. Since most of my 8x10 films are old J&C films, I always blame the problem for the old film. Now this problem happens to my fresh HP5 film, I think this uneven development maybe caused by the developer.

On the other hand, I have NEVER had any of this problem with my WP Tmax400 film. Maybe it is the film?

This is driving me crazy and I hate to waste those large sheets of film.

[jeroldharter]

I've never used the print tanks for negatives. The print tanks lack the center post that ports the added solutions to the bottom of the tank. I wonder if the band is from the initial pour of the developer. Are you using a CPP/CPA with a lift or filling by hand?

I have never used pyro developers but I understand that they oxidize quickly. There is a lot of surface area on a 16x20 sheet of film. Maybe you need more volume of developer? I assume you are doing a 5 minute water pre-soak.

Frustrating to do too many tests on 16x20 sheets of film.

[Robert Hall]

Hugo,

What direction was the mark as compared to rotation?

What Jobo processor?

was the processor rotating as the developer went into the tank?

[Hugo Zhang]

This is the only Jobo tank you can use for 16x20 film, even it is designed for print use.

I use 500ml solution A for 5 min. and 500ml solution B for 5 min. I presoak in water for 5 min as well.

I pour the solution in with the tank standing and then hand roll it on a roller.

[Hugo Zhang]

Hugo,

What direction was the mark as compared to rotation?

What Jobo processor?

was the processor rotating as the developer went into the tank?

Robert,

The direction is horizontal, same direction as rotation and now I wander if it is caused by pouring the solution in while the tank stands up.

[Robert Hall]

It makes me wonder if the developer is enough to cover the sheet well. With my 12x20 film I develop with 1.5 liters of solution to make sure the film is covered evenly with solution.

[Hugo Zhang]

Rober,

Do you use tray or Jobo tank for your 12x20 sheet? Maybe I should use 1,000ml next time.

Thanks,
Hugo

[Robert Hall]

I use a 3006 with an insert. The insert is falling apart a bit so at some point I will need to find some kind of replacement.

I have btzs tubes for 12x20 as well. I still use 1.5 liters for processing. The amount is not that much more, maybe 50 cents a sheet at the most. Considering the film is now about $15 a sheet, that is well worth the security of consistency.

[David Karp]

I don't use such large film, but I do pour the chemicals into my jobo drum while it is rotating. I created a rig out of parts purchased from Home Depot to allow me to do this with only two hands. http://www.largeformatphotography.in...ad.php?t=51174

[Robert Hall]

Dave, you are a genius