Does anyone have any experience or information on using Jobo MultiTank2 and the 4" X 5" sheet film reels for Black & White sheet film? What is the proper way to agitate the tank? Does on use constant agitation, or give the film a rest as you do with roll film? Will PMK Pyro work well with these tanks?

-- Tom Barkman (tbarkman@stlcc.cc.mo.us), September 25, 2001

Answers

I use a Jobo for 4x5 sheets. (It's been so long since I bought it, I don't remember if it's a "Multi-Tank2" or not, but it has sheet reels.)

I use inversion agitation. Be gentle, and careful. With a liter-and-a- half of solution in the tank, it's heavy.

Mine is a 2-reel affair, but I never load the top reel--just use it for a spacer to keep the bottom reel down. With 2 reels, you'd need 3 liters of solution--too heavy for safe handling, and no space for the developer to re-mix (locally depleted developer mixing with locally fresh developer) during inversion.

I tried PMK once, with fine results using this approach.

-- Charlie Strack (charlie_strack@sti.com), September 25, 2001.

I have used the large 4X5 Jobo tank only twice for hand processing. Once I mistakenly attempted to run it with 2 reels of film on my CPE2 processor. The motor on that unit will not turn the drum with the large tank and a normal charge of chemistry. So I pulled it off the machine and rolled it by hand in the bottom of my sink for the entire time. The film was developed fine but it was not much fun - don't do this! The other time I tried it with 1 roll and enough chemistry to cover the film for inversion processing - thats a lot of chemistry. I gave up on the idea because it seems wasteful. If you don't own a Jobo processor I suggest you might try continuously rotating the drum by hand on some kind of roller base. You can use less chemistry and get good results.

-- Henry Ambrose (henry@henryambrose.com), September 25, 2001.

I have the one reel Jobo tank with the 4x5 reels. I find it's a pain to use as an inversion tank. It takes a ton of chemistry, about 1.4 liters otherwise you will get uneven development. I found I can load the reels much faster by hand than by using the loader base. I never could get the knack of the thing, most often the film simply pops out of the grooves as it tries to go around. I figured by the time I got the thing loaded and closed up I would already be halfway through the process if I was using trays. Plus, using inversion agitation I've had problems with the emulsion sloughing off at the edges. I personally decided that using the tank with inversion is not worth it but you might decide otherwise. If you are set on using the Jobo tank manually try the roller base. It requires far less chemistry but you have to roll it continuously. The one reel tank is awkward to roll since it's so short but I think the two reel tank would be much easier to roll.

Many others on the large format message board have suggested Unicolor drums with a Beseler motor base for rotary development but I just went back to using trays for the time being.

-- Andy (akkup@mindspring.com), September 25, 2001.