jeffbuck@swcp.com
Date: 11/29/01-06:15:40 PM Z
SANDY: As a beginner in pyro and alt processes, I'm using PMK. I started
with it because of the suggestion that it is less quirky than the other
formulas. Would anyone else sitting in on this thread like to comment on the
general idea of PMK and pt/pd?? There's another thing, and this really kind
of drives me crazy: In their Platinum/Palladium Book, Sullivan & Weese
describe a very nifty homemade way of measuring density w/ a zone strip etc.,
the negative and two pieces of paper with small holes. You match the high and
low values of the negative to the corresponding densities on the strip, and
there's your density range, etc. etc. I loved the sound of this till I
realized this can't possibly work with a staining/tanning developer. I asked
Carl Weese about it, and he confirmed that it wouldn't work with pyro neg's.
Again (I'm quivering with rage), most densitometer's don't work w/ pyro neg's
either!! Besides, I can't think of anything that would be more fulfilling
that spending $600 on a densitometer.... See where I'm going here? Any
suggestions? -jeff buckels
Sandy King <sanking@clemson.edu> said:
> I sent this already two times but received error messages so don't
> know if it went to the list or not.
>
> Sandy King
>
>
>
>
> Linas wrote:
>
>
> > I think we are definitely over
> >staining and perhaps sometimes overexposing for the way we develop. As I've
> >told you off list, I've started using Pyrocat and really like these
> >negatives for Pd/Pt. Same "pyro look" to the prints, but less overall stain
> >and shorter print times.
>
> I am certainly guilty as charged. As I have said before, overexposure
> of negatives that are to be developed in a staining developer for
> alternative printing should be avoided like the plague. When you
> overexpose by a stop, even with non-staining developers, you can
> expect that this will translate into about a doubling of your
> exposure in printing. This changes a 10 minute exposure to 20
> minutes. It gets even worse with staining developers - you get the
> doubling of exposure, plus proportionally more stain *in the shadow*,
> so the net impact on exposure is even greater. This happens because
> it is primarily the shadow density that determines printing speed
> with developing out processes.
>
> If you have any question about whether or not your negatives are
> over-exposed, measure the density in Zone III, the first shadow zone
> where we typically like to see shadow detail. If this Zone measures
> over log 0.30 you are almost certainly over-exposing. Even with films
> that have b+f like HP5+ and BPF we should be able to keep the density
> of Zone III at about 0.30 or below. With a Zone III density of 0.30
> my carbon negatives with the BL bank print in about 10 minutes, not
> bad.
>
> Should I happen to overexpose HP5+ or BPF by a full stop, Zone III
> density will increase to approximately log 0.55 and printing
> exposures to about 30 minutes. The net impact on printing time is
> less with a film like FP4+, when with correct exposure I expect to
> see a Zone III density of about 0.20, but even with this film
> over-exposure by a stop results in more than a doubling of the
> printing time.
>
> However, the stain itself, with the correct exposure, is highly
> desirable for alternative printing since it helps to bump up the
> contrast to the desired CI with less development time, or in flat
> lighting situations allows us to make a printable negative when
> otherwise we could not. What we want, though, is very little stain in
> the shadows and a lot in the highlights. Lots of general stain,
> caused by over-agitation or oxidation, is very bad because it
> actually reduces contrast.
>
> I find that PMK is very prone to a general stain caused by
> over-agitation and/or oxidation, plus it has a history of streaking
> and staining. Given these problems, and the fact that it takes so
> much development time to reach the density range we need for
> alternative printing, my personal opinion is that PMK just does not
> make much sense for processes like carbon, Pt/Pd, kallitype, and
> vandyke that typically require a negative with a DR of 1.4 or higher.
> ABC+ or Pyrocat-HD make much more sense to me.
>
>
>
>
> Sandy King
>
>
>
>
> >
> >Remember how Bob Herbst said he doesn't use an after bath, uses normal
> >Kodak Fix, and even an acid stop bath (if I recall correctly)? Seems he is
> >actually making an effort to minimize stain. However, still plenty of stain
> >on his Wimberly WD2D negs, based on the ones he showed me after his
lecture.
> >
> >I'm looking forward to what Carl Weese has to say about Pyrocat after he
> >tests it.
> >
> >Linas Kudzma
>
>
> --
>
>
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