From: Joe Portale (jportale@gci-net.com)
Date: 07/21/01-10:32:29 AM Z
A simple way to help eliminate bromide drag in tube is to increase the
amount of developer. If you are currently using 6 ounces, increase it to 12.
The idea is to really flood the image area with developer. The more fluid
you have in the drum, the greater the sloshing around that will happen. It
is the turbulence of the developer moving around that helps with the bromide
drag. Also, if you are using one of the early motor bases, that doesn't
change direction or has an eccentric drive wheel that rocks the tube during
rotation, simply pick the off the base and turn it around ever couple of
minutes or so. This is a trick that I picked up from back in the good old
days when my darkroom was a hall closet.
Additionally, pre-soaking the film in tubes is critical. As I outlined in
an earlier email, place the film in a tray of water for a couple of minutes,
then fill the tube with water at developing temp, slid the film in, attach
lid, dump the water, add more pre-soak water and rotate on the base.
Someone off list accused me of being water wasteful and essentially raping
and pillaging the environment with this technique. I live in a desert and
water is precious. But the cost benefit analysis begs, is a little
conservation worth your negative? You can save more water by turning off
the shower while soaping up than you will use in this technique.
Must go now and start the grill, we are having Pygmy Owl for dinner. (Sorry,
inside joke)
Joe Portale
Tucson, AZ
----- Original Message -----
From: "Carl Weese" <cweese@earthlink.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Saturday, July 21, 2001 6:21 AM
Subject: Re: bromide drag
> Sandy (if you're receiving)
>
> I've been thinking about the print drum streak problem with staining
> formulas. I've gotten excellent negs without streaks, but also enough with
> streaks to avoid the technique. Tray development works fine anyhow, but
for
> those who have good reasons to prefer rotary processing...
>
> You mentioned not using an after-soak. How do you wash--in the drum or out
> and in a tray or washer? What I'm wondering is whether the streaking I've
> seen may be *only* in the stain, not the development, and so occured
during
> after-soak or wash. That would mean that drum rib streaks might not happen
> as long as the film is removed from the drum after the fix and given any
> further treatments in a tray. I'm much too busy with current work to run a
> test on this but experience of list members might hint at an answer. BTW,
> there's a completely different bromide drag problem with regular
> non-staining developers. D-76 (ID-11 should be the same) is the only
> standard developer I've seen that doesn't cause bromide drag streaking
when
> processing large film sheets in print drums.---Carl
> --
> web site with picture galleries
> and workshop information at:
>
> http://home.earthlink.net/~cweese/
>
> ----------
> >From: Sandy King <sanking@hubcap.clemson.edu>
> >To: alt-photo-process-l@sask.usask.ca
> >Subject: bromide drag
> >Date: Fri, Jul 20, 2001, 10:02 AM
> >
>
> > My understanding is that the Jobo rotation is such that it imparts
> > not only a horizontal rotation to the developing tubes but that the
> > tubes also oscillate on a vertical axis enough to eliminate the
> > effects of bromide drag. So, in short I think you have nothing to
> > worry about in this regards.
> >
> > As film develops bromide is released from the emulsion. If the
> > rotation of agitation is only in one direction ( or around a central
> > axis) the excess bromide produced locally will produce uneven
> > development, usually streaks of greater density with rotation
> > processing, around this area. Vigorous agitation breaks up the local
> > concentration of bromide and distributes it over the entire surface
> > of the film.
> >
> >
> >
> > Sandy King
> >
> >
> >
> >
> >> >Sandy King wrote:
> >>
> >>>Also, when developing film on motor bases like the >Beseler or
> >>>Unicolor bases you should remove the tube >from the motor every
> >>>couple of minutes and give it >about 10-15 seconds of up and down
> >>>agitation, >otherwise the constant agitation fore and aft
> >>>will >cause bromide drag.
> >>
> >>Sandy,
> >>
> >>Perhaps this has been discussed earlier. Can you explain what
> >>bromide drag is? I use a Jobo CPP-2 which rotates in one direction
> >>about 1 and a half turns, then stops and rotates in the other
> >>direction about 1 and a half turns and repeats the cycle. Would
> >>this action help to eliminate bromide drag? I don't think I have
> >>ever had a problem with a negative that would have been
> >>related to something like bromide drag. But I would like to
> >>understand the issue better.
> >>
> >>Jim
> >
> >
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