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georgl
13-Dec-2011, 10:10
I'm developing my b&w-film since years now without a single problem - but sheet film drives me insane!

I've acquired a Jobo 2830 because it takes two sheets and is affordable (Jobo Expert in Germany is now 500$+ and takes 330ml of chemical with an uneven number of sheets!).

I only handled the film with gloves, used demineralized water, 250ml of fluid, lowest concentration (in my case 1+14) to avoid fast development reaction and rotate the drum on a leveled base with approx. 30min-1 and a turn in direction every 30s.
The most critical moment seems to be the first tilting when the developer slowly enters the drum - it takes me at least 5s to tilt the drum and make a first revolution - too long?

Also the edges don't seem to be properly developed (brownish) - despite good film position within the drum.

I've read in older posts that people use the Jobo 2830 without a problem!?

Any advice? Alternative process?

Greg Davis
13-Dec-2011, 14:04
You may need more liquid. You have enough to cover the film properly, but may not have enough active developer to process the surface area of film. Try 400mL of developer and see if you get better results.

-Greg

ic-racer
13-Dec-2011, 14:24
3 years using the 2800 drums with no problems.

2850 drum I use 470ml Tmax developer
2830 drum I use 260ml Tmax developer

No prewash, usual Stop and Fix.

If you are using a lift then 1:14 may overload it as you would want to keep volume less than 1000ml. If you are just rolling it on the table you could probably fill it with more than 1000ml and use a dilute solution.

I'm not sure why you want a dilute solution, as the cost is the same because you need the same amount of developer to process the film, irrespective of the dilution.

georgl
14-Dec-2011, 01:18
Thank you!

I'm using a dilute solution because it's a quite exotic developer (low contrast) for orthochromatic document film I got for a few € - just for testing before I switch to TMY2. The concentration is given between 1+9 to 1+14. Does it work better with conventional developer? I want to be sure before I ruin 7$-sheets that took me hours to make...

1000ml? How do you get as much fluid into the cap? i think it takes 400ml max. ? Or is it better to get a CPP2 with lift?

ic-racer
14-Dec-2011, 09:13
Though the thread below is about Rodinal, I have used the technique to process high contrast film with a dilute solution.

http://www.largeformatphotography.info/forum/showthread.php?t=23322

georgl
15-Dec-2011, 06:25
Thanks. So you are all using a machine with lift for faster filling and mor volume?

Greg Davis
15-Dec-2011, 07:20
I use the Jobo CPA-2 with a lift when processing my C-41 films, but I use just a regular Unicolor motor base for processing black-and-white, or sometimes the non-motorized hand roller base Jobo used to make.

georgl
19-Dec-2011, 11:41
I've tried again on the weekend - this time I maxed out the filling (>375ml) and the speed (less then 5s from tilting to first full rotation.

Still some streaks and development problems along the edges... I don't understand why it works for some and not for others... Do I really have to get the 500$ expert drum?

I added a developed, unexposed (!) scan (as a positive, it look like this on the table) from a negative:
http://imageshack.us/photo/my-images/860/8x10streifen.jpg/

It seems like I have serious problems despite meticulous cleaning of the equipment and use of demineralized water... Or could "normal" developer+film already solve the problem?

georgl
26-Dec-2011, 01:15
Yesterday I've tried tray development to find a solution and the result is quite surprising to me. Both, the streaks and the uneven edge development are caused by the developer! Different developer (although without midtones, hence it's too contrast with the document film) and all problems are gone! It has nothing to do with the drum or processing itself!