From: Sandy King (sanking@clemson.edu)
Date: 09/20/02-08:31:04 AM Z
Victor:
Thanks for sharing the results of your recent stain tests with a pyro
developed negative. Your findings tend to confirm at least two of my
opinions about the use of the afterbath: 1) the extra proportionate
stain that it causes is either too small to be of any consequence,
or, as your results with TRI-X indicate, it may not be proportionate
stain at all, but general, undesirable stain, and 2) results vary a
lot in actual tests, depending on choice of film. And, based on
previous comments made to this list, results vary a lot among
individuals in different parts of the country -- difference in the
water I assume. I personally mix all of my stock solutions with
distilled water, but use tap for the working solutions.
I have conducted similar tests in the past with both PMK, ABC+ and
PYROCAT, using rather tightly controlled parameters, i.e. exposure
with a light integrator accurate to 1/100 of a second, use of a step
wedge, development in tubes with tight temperature control. The
results of my tests with FP4+, HP5+ and TRI-X were not very different
from yours. What I found, in general, was that most films show more
general stain from the afterbath, with little or no increase in
proportionate density. I conclude that the afterbath is just not
worth the trouble and have settled on a processing routine that
includes fixing in an alkaline fixer and from there directly to the
wash.
Will sodium carbonate give more stain than sodium metaborate if used
as an afterbath? Although I have not tried sodium carbonate my
suspicion is that any increase in stain that you see with it will be
an increase in general, not proportionate stain.
Finally, irrespective of its reputation for not staining well I get a
very nice stain with T-MAX 100 and Pyrocat. Visually the negatives
look rather neutral in color but when you compare measurements with
the visual and blue channel of the densitometer you will find quite a
large difference in measurement.
Sandy King
>Please forgive the long post.
>There has been some discussion on this news group and others
>regarding the effectiveness (or lack of same) of placing
>Pyro-developed film back into the used developer after it has been
>fixed. The consensus seems to be that there is no advantage to
>increase stain proportionately, but that the afterbath only adds
>overall stain evenly. What follows are the results of some
>preliminary tests done with FP4 and TriX only.
> The parameters: I developed the film in a Jobo CPP2 using Rollo
>Pyro. Density reading were taken with an old MacBeth TD504 with the
>blue channel. Film exposures were not made in a lab-controlled
>environment, but duplicate shots were made on days of consistent
>bright overcast lighting. I understand that sodium metaborate may
>be used in place of the used developer with the advantage that it is
>less likely to increase B+F.
>My results for FP4:
> With sodium metaborate as an afterbath I found no increase in
>density at all, not even at relatively high maximum densities, such
>as in one case, 1.65. The films both with and without the after
>bath had exactly the same densities.
> For identically exposed films where one is placed into used
>developer after fixing I found some proportionate increase in
>density. The B+F was the same for both films and up to about .80
>they were about the same. At about 1.00 the film from the afterbath
>had about .04 higher density and at about 1.35 it had about .08
>higher density. So there seemed to be some proportionate increase
>in density using the developer for an afterbath, but not so much as
>to be worth the trouble. The same increase would probably result
>from slightly longer developing times.
>My results for TriX:
> I made three identical exposures and the film was developed to a
>higher density (to be used for POP). One film was placed in sodium
>metaborate and here the B+F was identical to the film that received
>no afterbath. Again there was some proportionate increase in
>density but the highest (at densities around 2.00) was only about
>.08. Again hardly worth the trouble of the afterbath.
> However, for the film placed in used developer as a afterbath, the
>B+F showed an increase of 0.12 and this same increase was added
>evenly throughout the range of densities up to 2.00. So in this
>case, there definitely was no advantage to using the developer as an
>afterbath.
> All films received a long final rinse (20-30 minutes). For me,
>the FP4 only acquires the stain color after a long rinse.
>
> In an article by Maxim M. Muir, "Pyro Tips and Tricks", he
>mentions the possibility of more effectively increasing stain by
>using sodium carbonate rather than sodium metaborate or used
>developer. Has anyone tried this? I wonder, with the reputation
>that T-max 100 has for not staining well, whether this might work
>better on this film. Considering this film's advantage for less
>reciprocity failure at long exposures, and the fact that it is
>available in ReadyLoad, it would be nice if it responded better to
>Pyro development. Has anyone tried sodium carbonate as an afterbath
>for any film?
>Victor Loverro
>
>
>
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