DEAR TIM,
Thanks so much for doing and posting your extensive testing. I
believe stand development was good enough for the majority of Atget's photos.
Of course, he was probably using plates and his emulsions were probably more
compatible with stand development...just guessing.
*****BUT, and this is a big BUT, (as it were! LOL!!!) stand development is
supposed to be done horizontally, not vertically. The bromide drag is due to
good ol' Sir Isaac Newton's apple, gravity!!! I am not suggesting that the
very short and widely spaced agitation periods are not beneficial but you may
find they are less necessary if you lay (or even tape) the film flat,
horizontally at the bottom of a tray. You speak of tanks and holders which
leads me to believe that the film is vertical in the developer.
CHEERS!
BOB
-----Original Message-----
From: pure-silver-bounce@xxxxxxxxxxxxx
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Tim Daneliuk
Sent: Sunday, February 07, 2021 6:01 PM
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] More (Semi) Standing Around
Notwithstanding the fair warnings I've gotten here, I have persisted
in continuing to test highly dilute Pyrocat-HD in a variety of
agitation models.
Results below based on diluting the developer in distilled water and
timing the development with my temperature-driven development time.
In general, my darkroom sits between 68-70F anyway, so the adjustments
the timer is making are small.
Tests include Kodak TXT, Agfa APX-100, and Ilford FP4+, all in 4x5 sheetfilm.
Observations
- Yup, pure stand development (agitate once and walk away for an hour)
is flakey and prone to very bad bromide drag, at least with
the hangers I used for the test.
- Dilutions of 1.5:1:150 seem to work well if the film is agitated
and initial minute or two, and then agitated 10-15 seconds at the
1/3 and 2/3 total time points. (This is known as "Semi-Stand" or
"Extreme Minimal Agitation" among the cognoscenti.)
- These films seem to like about 30 min of semi-stand time with
initial agitation around 90 seconds, and then again for 10-15 seconds
at the 10- and 20 minute marks.
- Tri-X (at least TXT - how many versions of Tri-X have there been?
Many, methinks.) stains most. Neither APX 100 or FP4+ stain anywhere
near as much.
- All three films demonstrate near box speed when processed this way.
Base on observation of the detail in Zone III (not desiometrically
confirmed) TXT seems to show up at ASA 250, APX 100 at ASA 80, and
FP4+ at ASA 100. When I get closer to final, consistent practice,
I'll probably do some testing of speed with a bit more rigor.
- I tried some FP4+ with an even higher dilution of 1.5:1:200 and
semi-stand developed for 40 minutes. It's hard to tell from the
still-wet negatives, but it appears that the higher dilution definitely
causes some speed loss. Then again, as noted below, my meters just
hated the cold this morning and both took a nap mid-shooting.
- I normally process with hangers in an open tank. I had purchased a
Yankee 4x5 tank for other reasons and thought I'd give that a run.
I was forewarned by the experts that this would not end well and it
hasn't.
The tank's construction encourages bromide drag even with periodic
agitations.
Ask questions, share your own experiences, or call me nuts, it's all welcome :)
I will say that this has gotten me shooting 4x5 very actively again because of
the
joy of discovery. When I got up this morning, it was -6F. By noon, I was
trudging through
calf-deep snow in a forest by a river with a full backpack on and a tripod in
my hand.
It was a balmy 0F at that point. Both my Zone VI and new Reveni Labs meter (or
their
batteries) conked out in that weather, even though both were inside a jacket
pocket.
--
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Tim Daneliuk tundra@xxxxxxxxxxxxxx
PGP Key: http://www.tundraware.com/PGP/
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