Pre-soak for manual 4x5 B&W development in a Jobo tank?
I have a stack of negatives I'd like to develop soon.
Since my Jobo ATL 1500 was recently stolen, but my tanks and reels were stored elsewhere, I plan on loading the films onto the reels (looks like 6 sheets per reel, 3 on each side) and using the smallest of the tanks (holds one reel) for manual developing. It should take about 1l of chemicals to cover the top of films for regular stand/inversion developing, and about a third of that for roller/continuous agitation development.
I haven't yet decided on whether I'll roll them back and forth on the counter top or in a sink full of tempered water (I have a rubber stopper to seal the lid) or simply use the regular inversion method. I might try both and see how the results look.
With the ATL, it always ran a "pre-soak" cycle prior to adding the chemicals. Is this needed when using stand/inversion developing? Is it needed at all, or just something Jobo added at some point for a reason that no longer applies?
The emulsions in question are Agfa APX-100 and Arista EDU 100. I'll be developing in Rodinal.
Thanks for any information.
Re: Pre-soak for manual 4x5 B&W development in a Jobo tank?
It depends - mostly upon what developer is used and whether it's being used one-shot or saved and rused multiple times. For most mainstream devs a presoak /rinse is really not necessary and in some cases (Ilford comes to mind but, I don't really remember for certain) it is specifically recommended to not presoak.
My personal usage is D-76 or D-23 and if used one shot than I do not pre soak but if I'm saving the dev and re-using it then I'll presoak. I really don't think it matters either way in my specific case but, that's what I do.
EDIT: I do not use rodinal so cannot realy say one way or the other. My guess is that it doesn't make any real difference either way.
Re: Pre-soak for manual 4x5 B&W development in a Jobo tank?
My experience is with sheet film in my darkroom with JOBO drums on a STARK SST4 with continuous agitation. Films: FP4+ and HP5+
Rodinal 1:25... With or without a pre-soak water bath, developing times are the same
Rodinal 1:100... With a pre-soak water bath increase the development time by 20%. I also double the amount of recommended developer for the JOBO tank. Read this somewheres back in the past. Not sure if it really matters, but since the cost of the developer at this dilution is increased by pennies, I do it.
Rodinal 1:50... I increase the development time by 10% if I pre-soak the film in a water bath. Can't say for sure if it really matters though.
The above I have never tested by using a pre-soak verses no pre-soak. After developing a lot of film over the years, the above just represents my collective experiences.
Re: Pre-soak for manual 4x5 B&W development in a Jobo tank?
I've used a Jobo CPP-2 for 20 years. I never use a pre-soak with black and white film.
Re: Pre-soak for manual 4x5 B&W development in a Jobo tank?
Not sure the presoak is needed when doing regular inversion or when rotating. You could do a few test shots and check if it leads to different results.
I use a presoak when doing large format for 2 reasons. The first is to increase the development time a bit. Especially in the summer in a warm darkroom my N-2 times get too short and any increase is welcome. The second reason is that i use XTOL in a replenishment regime and the presoak gets rid of the anti-halation layer, so my stock solution doesn't turn into some dark and dirty liquid.
I find replenishment ideal for the large volumes even the small Jobo tanks take. For rotation you will need about 300 ml, for inversion you will need 1200 ml to fill the tank and conver the sheets. With the small amounts of fluid when doing rotation you need to take care to use neough active developer: 6 sheets in 1+1 XTOL is just enough.
Re: Pre-soak for manual 4x5 B&W development in a Jobo tank?
I have never found a presoak to be necessary in B&W or color, in manual drum, tray or rotation processing.
Re: Pre-soak for manual 4x5 B&W development in a Jobo tank?
I use a pre-soak when rotary processing 4 sheets in a Jobo 2500 tank, not to aid the absorption of the developer, but to bring the film and tank interior up to temp since my darkroom is outside and can be quite cold in winter time (come to think on it, it can be quite cold in summer time too :))
I try not to put more than 4 sheets in at a time even though 6 are possible......that way i make sure there's enough developing agents available especially with Pyrocat HD.
Mike
Re: Pre-soak for manual 4x5 B&W development in a Jobo tank?
For the OP: I would try to replicate your Jobo process if rotating manually, just to keep the variables down. For inversion, especially one-shot developer use, I don't think it matters unless you need to warm the tank and film. Obviously, run a test to confirm your times before running a big batch!
I stopped using a pre-soak with HP5 and Delta films when I started using a two-bath developer. The exception is Bergger 400. That seems happier with a pre-soak and a long first bath time (Delta is typically 5 minutes in each bath. Bergger wants 17 minutes in bath A, which seems common for metol developers.).
Re: Pre-soak for manual 4x5 B&W development in a Jobo tank?
I used to presoak in 15xx and Experts and tbh, never noticed any difference. So for me, I stopped presoaks for Jobo, and hand inversion.
Re: Pre-soak for manual 4x5 B&W development in a Jobo tank?
FWIW I do pre-soak for regular inversion in a JOBO tank. I use Pyrocat HD.