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Re: Pyro ABC+
Carl,
Thank you for your reply. The Pyro was mixed at about 80 degrees F in
distilled water. Too warm? Is there a better temp I should be using? Is it
worth continuing testing after filtering off the precipitate? I just hate
to pitch 1000ml of pyro A watching all those $$$ run down the drain can be
heartbreaking. Can pyro be mixed in smaller quantities?, I think I am using
the formula published in your article in Darkroom magazine. Do you have any
tips for mixing solution A that might help? Dissolving that much powdered
chemistry in that much water seems to almost be reaching the point of
supersaturation. Heck, when you mix the soup into a working solution at
those dilutions it has to be pretty saturated.
The TXP is fresh and I am rating it at ISO 200. Do my Zone V or VIII
readings seem at all closer? Perhaps my ISO needs to be adjusted? Visually
the negs look a bit on the thin side to me compared to my negs developed in
HC110 Dil. B. But then again I have alway leaned twords a "meaty" negative.
I guess its back to the drawing board then?
Thanks again for your valuable input. I hope to get this stuff rocking and
rolling before the summers end. (laughing)
Marty
At 06:54 AM 4/29/01 -0400, you wrote:
>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
>
>