Jobo 2850 and 8x10 Film Processing

[EdC]

Courtesy of one of our fine vendors, I've been using a Jobo 2850 for processing 8x10 film. Things seem to work well, but there are a few nagging questions rattling around in my mind.

I am using Photographers Formulary TF-4 and following their recommendation for a water stop bath. What I've been doing for that is filling the tank through the lid after removing the flexible stopper cap and letting the water run but doing at least two full water changes (dumping and refilling) during the 5 minute wash for this. For the washing process after fixing, I am removing the tank lid and flexible cap, and then running water under force for 20 minutes, with at least four full water changes during that time frame.

I've not seen any detailed commentary on others using the 2850 (other than general comments on developing), so I thought I would check in and see if there are any suggestions on a better way of handling the water stop bath and the film washing stage. I have a very large Zone VI print washer, and could use that for the 8x10 film, but since I am not using 8x10 as much as 4x5 or medium format, I didn't want to have to deal with filling the entire thing up in order to use it for washing just 2-3 sheets of film.

Appreciate the suggestions!

Ed

[Graham Patterson]

Are you doing manual rotation, or are you using a processor? I am also assuming that you are doing 1-2 sheets against the sides of the tank in 'print mode', and not using an insert. Cup or funnel lid?

I use a plain water rinse between the developer and the fix (TF-4) on my CPE2+, for 1 minute continuous rotation. For washing I do 1, 2, 4, and 8 minutes of continuous rotation with plain water. The wash volume per pass is the same as my processing volume.

Sometimes I add a final rinse in a tray using plain water if the anti-hallation dye has not completely cleared. The fix is gone by then. Then wetting agent and drying.

If you are doing manual rotation then the extra 15 minutes of rotation is a lot of effort. The only trouble with doing force washing is that you need a tank/drum with a center column and funnel lid to do it, otherwise you can't get a hose to the bottom without risking emulsion damage.

[EdC]

Thanks for the commentary, Graham! Let me offer a few more bits of information.

Yes, I am doing manual rotation, with 2 sheets in the 2850. I vaguely recall inserts being available for 8x10, but haven't seen mention of those for a very long time. The lid I am using is the cup version. I have checked Catlabs and did not see any sort of funnel lid for this tank.

In regards to the wash process, I am not using rotation for either the water stop bath or film washing stage. I use the faucet flowing directly into the cup lid in order to fill the tank with water for the stop bath step, and just manually dump water two or three times during that five minute process to get more water exchange. In that same vein, I remove the cup lid entirely during the washing stage after the fixing step. Then run water directly into the tank continuously and do a complete dump every five minutes or so in order to get everything flushed out as much as possible for the film washing stage. I'd be happy to make use of a center column with a funnel lid. But, while I could piece together a center column, I have not seen a funnel lid for this tank.

Thanks,

Ed

[dave_whatever]

Basically grab the lid of any of 2500 series film tank - the funnel lids for these tanks are all the same and fit the print drums, assuming you have the centre core. The 2800 print drums and 2500 film tanks are the same size externally. In fact other than the internal ribs, and the lids/cores, the 2800 drums are basically the same as the equivalent 2500 tanks.

[EdC]

Thank you, Dave! Followed your advice and got in touch with Omer.

Ed