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Re: Pyro ABC+

Martin,

The A solution should last months, so something must be wrong with your
batch. Did you use distilled water? Did you mix at too high a temperature?
(It's easier to mix at high temperature, but more stable if mixed at room
temp)

Next, the film base numbers are too high. TXT is a low-fog film. Regular
developers should give fb+f numbers of .07 or .08, and a pyro neg should
show only the faintest hint of stain color and a blue-channel reading of .11
or .12 in Zone 0. If the film is old it can show a heavier fog, and of
course spoiled chemistry can fog it too.

You need a batch of developer that stays in solution, and a test set of
negatives that don't show excessive fb+f levels, before you you can get any
farther tuning in results.---Carl

--
            Web site with workshop information and

                  **NEW PICTURE GALLERIES**

            http://home.earthlink.net/~cweese/

----------
>From: Martin Salowey <mnspeebs@castle.net>
>To: alt-photo-process-l@sask.usask.ca
>Subject: Pyro ABC+
>Date: Sat, Apr 28, 2001, 5:15 PM
>

> Hi All,
>
> I have been working on standardizing Tri-X sheet film processing times with
> the ABC+ Leban Formula diluted 1:2:75 @72 degrees F in a Jobo Expert drum
> with the rotation set at 4.
>
> I have a couple of questions to get me headed off in the right direction.
>
>
> 1. Should fresh stock solution A after sitting a few days in a room at
> about 68 degrees F form a precipitate? I went to process some film this
> afternoon and was shocked to find my fresh stock, mixed less than a week
> ago, has a fuzzy precipitate (looks kind of like pyro crystals). I am
> assuming it is the pyro since the solution is rather saturated, but does
> not seem to want to dissolve when gently heated in a bain marie. Anybody
> else ever have this problem? The pyro was purchased in 1 lb. quantities
> from Photographers Formulary.
>
> 2. I realize that densitometric evaluation is really only a point of
> departure with pyro but would like to see if my results are heading in the
> right direction. (Mr. Wesse are you out there?) The densities are for a
> given exposure(zone) and read for both neutral and yellow (B) channels.
> (Exposure Neutral/Yellow) These tests were processed in ABC+ 1:2:75 @ 72
> degrees F for 8.5 minutes in the 4x5 Jobo expert drum at a rotation of 4.
>
>
> 1. fb+f    .12/.27
> 2. Zone 0  .24/.45
> 3. Zone I  .32/.58
> 4. Zone III .45/.87
> 5. Zone V .68/1.18
> 6. Zone VIII 1.31/2.06
>
> Thank you in advance for your input.
>
> Marty