Archived posting to the Leica Users Group, 2002/01/04
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jobo is not misleading anyone!
it's largely because of the "100ml Xtol rule", that for each 8x10
equivalent of film (one 135 or 120, half a 220) you should have 100ml
of stock. when you use xtol (1+3), this means you need _much_ more volume
for working solution than the film itself; i.e., you cannot fill up the tank
with all the reels it will hold. anshell and troop make a big deal about
having sufficient developer stock per roll in their book... so i follow the
recommendation.
hence, for my developing with jobo tanks and inversion agitation:
(i manually agitate my B&W)
jobo xtol stock total
1 roll 1520 125 500
2 rolls 1510+1530 250 1000
3 rolls 1520+1530 300 1200
physically, the above jobo configurations can hold 2, 4, and 5 reels of
35mm respectively, but because of the solution volume requirements, i get
1, 2 and 3 reels.
the only unpleasant part is the time to fill and empty the tanks becomes
much more of an issue, and inverting 1.2 liters for agitation is like
juggling full plastic coke bottles. it would be nice to pop the reels
into a small tank after the stop bath, but i've not figured out the
logistics of doing that.
the situation is much exacerbated with rotary because in rotary processing
you use about half the volume of solution in a tank than you would using
inversion. hence, to strictly adhere to the 100ml xtol rule, you'd need the
1510+1530 tank for _one_ roll... and that'a _big_ tank for _one_ roll!
- -rei
> From: John Straus <Mail@slideone.com>
>
> on 1/4/02 11:45 AM, Dave Stratton at stratton@gci.net wrote:
>
> > I use the Jobo CPE (with lift) for processing B&W. I would recommend that
> > you do get a lift for the processor...it really does make life a lot more
> > pleasant. Also, I use Xtol (1:3) to process Tmax film and obtain great
> > results...but a caution...I have found that I must use 3 oz (~90 ml) of Xtol
> > per roll, thus I have to use ~ 360 ml solution per roll. With a little over
> > a 600 ml liquid limit, the max number of rolls I process at a time is 2 (and
> > doing the numbers I am pushing my limits).
> >
> > I still find the cpe a great way to do film...I just find something to do in
> > the darkroom for the ~ 30min processing time. If one wants to process more
> > than two rolls use Xtol (1:2), or even Xtol (1:1). Not as successful for
> > me, but still good results.
>
> Thanks for the heads up on the limits of the CPE-2. So tell me why they list
> the capacity @ 5 rolls of 35mm when that is not possible??? Truly misleading
> until you read the fine print...
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