[pure-silver] Re: PYRO Processing Questions
- From: "David Swinnard" <davidswinnard@xxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Fri, 21 Nov 2008 08:30:03 -0800
I've been using Pyrocat HD in a Jobo Expert drum for my 4x5 for a couple of
years (slowest rotation). I chose to mix and use the glycol version. I
just replaced the last bit of my solution A (dev agents) with a new mix,
after two and a half years, as I thought it might be getting a bit "weak". A
comparison between the new and old "A" versions did reveal the old stuff
(which showed some feathery precipitates at the bottom of the bottle) was in
fact somewhat weak. Images were usable from it, but about a grade soft with
thinner shadow zones.
Before settling on the Pyrocat HD I tried Rollo-Pyro from B&S as I'd read it
dealt well with the excess oxidation in rotary processing. It was OK, but
at that time I wasn't using enough of it to keep it from getting old. Now
that I'm mixing PC-HD (glycol) that isn't a problem as I can mix up new as
the need arises (and I'm not shipping liquids with their attendant shipping
costs north across the old 49th).
Testing settled the development time issues - my 4x5 film has always been
rotary processed (Unicolor drum/motor base, Jobo). My roll films are still
small tank processes, and again, a quick bit of testing shows me the times.
Initial start times were plucked from one web site or other.
Dave
_____
From: pure-silver-bounce@xxxxxxxxxxxxx
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Speedy
Sent: Friday, November 21, 2008 7:51 AM
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] PYRO Processing Questions
I am interested in trying Pyro.
I commonly develop my negatives on a Jobo processor.
How does Pyro do with this type of agitation?
As a starting point - how would development time
need to be adjusted for rotary agitation?
THANKS!
Speedy
----------------------------
> From: bobkiss@xxxxxxxxxxxxx
> To: pure-silver@xxxxxxxxxxxxx
> Subject: [pure-silver] Re: Learning from Printing (was Difference in Paper
Processing Speed)
> Date: Wed, 19 Nov 2008 21:38:50 -0400
>
> DEAR ELIAS,
> Yes, pyro is toxic but anyone who thinks that they can stick their
> hands into "normal" processing chemistry (MQ developers, fixer, toners) is
> living in never-never land.
> You should ALWAYS use gloves when processing. I spend years
> chelating both metal ions and phenols (the basis of most developing
agents)
> out of my liver because some foolish photo instructors in the late 60s and
> early 70s said that "you are not a real photographer unless you put your
> hands in the tanks/trays".
> You can buy PMK from Photographer's Formulary. Just mix according
> to directions. Easier than most cookbook recipes.
> There is an ENORMOUS difference in acutance between PMK and any
> ascorbic acid developer such as Xtol. Further, PMK seems to do the
> impossible; it combines acutance with fine grain. The acutance is due to
> both the edge effects produced by the dilute metol developer and the
tanning
> of the emulsion (differential thickness related to density) produced by
the
> pyro development. The fine grain is due to the fact that the stain image
> produced by the pyro is effectively grainless and the very gentle silver
> development due to the dilute metol development produces fine silver
grains
> as well.
> I have tried Xtol and it pales in comparison with the shadow
> separation, highlight range, and acutance produced in the films I
mentioned
> (T-max 400, HP5, FP4, FUJI ACROS all in 2 1/4, 4X5 and 8X10) processed in
> PMK.
> Pyro is both toxic and carcinogenic "in sufficient quantities",
> quoting THE BOOK OF PYRO by Gordon Hutchins. The developer solution uses
10
> ml of the pyro solution in one liter (1000ml) so is VERY dilute. Just wear
> gloves.
> Because I want to be able to print my negatives both in
> silver-gelatin and platinum/palladium, pyro developers are perfect. I
> regularly make 16X20 silver-gelatin prints (often significantly cropped)
> from my 'Blad 2 1/4 square T-max 400 or HP-5 negs. I love them. I have
> found no dev that rivals the combination of fine grain, dynamic range
> (ability to capture scene brightness range), and acutance.
> If you are worried about the toxicity try Pyrocat HD which uses
> pyrocatichol (sp?) which is much less toxic than pyrogallol in PMK.
PYROCAT
> HD is also available from Photographer's Formulary.
> CHEERS
> BOB
>
>
> -----Original Message-----
> From: pure-silver-bounce@xxxxxxxxxxxxx
> [mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Dennis Purdy
> Sent: Wednesday, November 19, 2008 6:25 PM
> To: pure-silver@xxxxxxxxxxxxx
> Subject: [pure-silver] Re: Learning from Printing (was Difference in Paper
> Processing Speed)
>
>
> On Nov 19, 2008, at 13:11, Sauerwald Mark wrote:
>
> > In my experience, there are few people who have tried pyro and don't
> > have a strong opinion on it, although I am one of those few. Many of
> > it's adherants are religious in their praise of the wonder developer.
> > I went through a phase where I experimented with it, and managed to
> > get some good images, but ended up going back to my old standby of
> > HC-110. I may dabble in Pyro again in the future, but I found it
> > difficult to get results which were as consistent with Pyro as I get
> > with HC-110.
>
> My experience is the same as Mark's in that I have been swayed several
> times (at least 5) to give it a try and have processed a lot of both
> 120 roll film and sheet film and am unable to identify what is special
> about it. Maybe it depends on the film you use or the light source you
> print with. I have tried it on 8x10 film and printed it in platinum as
> well and see no reason to work with the nasty stuff. Most recently I
> processed about 15 rolls of 120 ACROS in PMK and found it printed just
> fine, kind of like if I processed it in Xtol.
> Dennis
>
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