From: Sandy King (sanking@hubcap.clemson.edu)
Date: 07/20/01-11:30:38 PM Z
Carl,
I am responding to your message indirectly through Joe's copy.
I do not give film an after-soak with staining developers because my
tests show that the stain that is added at this point is mostly b+f
stain that simply increases printing time but does not enhance image
quality or increase overall contrast. I always wash the film in a
tray of running water outside the tube.
As to the problem of stain that resulted from the ribs of the tube I
am going to presume that this took place on the back *non-emulsion*
side of the film since I can think of no logical reason it would
happen on the emulsion side. I further presume that the stain was a
line of less density, indicating that the area under the ribs
received less of an exchange of developer than the areas immediately
adjacent to it. If this is indeed the case logic would suggest that
the problem could be eliminated or its effects minimized by the
following.
1. A very thorough pre-soak of the film.
2. Making sure that the back of the film receives a constant and
consistent flow of developer. Rocking the tubes in addition to the
fore and aft movement would probably help here. It might also help to
adjust the spacers so that the film can move slightly around from
side to side during processing.
3. I also believe that Joe's suggestion that a greater quantity of
solution might help, though the amount I use is not all that great
(one liter per sheet of 12X20 in a 16X20 drum.
I have just processed about 40 12X20 sheets in Beseler 16X20 color
print drums, about half with ABC+, the other half with PYROCAT-HD,
and see no evidence of anything other than very even development.
Procedure as follows.
1. Place the film in the drums, add plain water at development
temperature and pre-soak with motor-base agitation for five minutes.
2. Develop for the required time on a motor-base agitator, reversing
movement, removing the drum at 2 minute intervals for vertical
rocking to counter the possibility of bromide drag.
2. 20 second acetic acid stop bath.
3. Fix in Ammonium Thiosulfate fixer (alkaline) for 6 minutes.
4. Remove from drum and wash in running water for 15 minutes.
I would add the design of the ribs and spacing (loose) of a piece of
12X20 film in a 16X20 Beseleer drum is such that you get a rather
good exchange of chemicals on the back of the film, especially helped
by occasional vertical rocking.
Sandy King
>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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