From: Witho Worms en Jorien van Santen (verzet13@xs4all.nl)
Date: 11/01/01-02:52:56 AM Z
You can make an easy comparison by printing a pyrocat developed stepwedge
together with a standard stepwedge. You will be able to see at what density
you get a paper white.
I measure my pyrocat negatives with a deep blue filter, a non standard but
one that affects most strongly the readings. I also have a halogen lamp
built in my densitometer. This and also the type of printing technique that
you will use will affect your readings. But if you standardize them you will
have a workable set of data for yourself.
Regards,
Witho
----- Original Message -----
From: "clay" <wcharmon@wt.net>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Thursday, November 01, 2001 4:36 AM
Subject: Re: step wedges; POP and gold toner
> Sandy:
>
> I decided to try your pyrocat HD developer for a batch of negatives that I
> will use for platinum printing. I normally use D-76 and a densitometer to
> figure shadow density versus highlight density and then plan the contrast
> mixture accordingly. Is there any rule of thumb for converting
transmission
> density of the stained negatives to an equivalent for unstained negatives?
> Is the actinic filter effect less than that of a yellow-green rollo-pyro
> stained negative? I hope it is, because my only beef with pyro has been
the
> incredibly long printing times. BTW, I can already tell that the pyrocat
> handles highlights as well as pyro. One of the images has a lit lamp, and
> there is NO halation, while the D-76 negatives have a great deal when
> imaging a similar subject.
>
>
> Thanks,
>
> Clay Harmon
> ----------
> >From: Sandy King <sanking@clemson.edu>
> >To: alt-photo-process-l@skyway.usask.ca
> >Subject: Re: step wedges; POP and gold toner
> >Date: Wed, Oct 31, 2001, 5:30 PM
> >
>
> >Shannon,
> >
> >Much of the previous discussion has focused on making prints. Your
> >problem appears to be in the density of your negatives.
> >
> >That being indeed the case, and correct me if I misunderstood you,
> >you will need to adjust the exposure of your negatives by rating the
> >film at a higher EI. I can't tell you exactly how much because that
> >will depend on several factors, including how you meter, developer in
> >use and film. However, try doubling or even quadrupling the EI that
> >you use to meter.
> >
> >If the question is merely that the shadows in your prints are too
> >dense by about two stops, that represents an overexposure in printing
> >of about two stops, equivalent to a density difference of 0.60.
> >Reduce your exposures by a factor of .25 or .50. For example, if the
> >offending exposure is 100 seconds, reduce to 50 seconds to for a
> >density change of minute 0.30, or to 25 seconds for a change of 0.60.
> >
> >With all POP processes the key to good contrast is to keep the
> >density of your negatives low in the shadows. Anytime negative shadow
> >density goes over about 0.40 it becomes very difficult to get good
> >contrast from POP processes because of their self-masking feature.
> >Lacking a densitometer, a rough guide to 0.35 on the exposing
> >negative would Step Four on the transmission step wedge (Stouffer,
> >Kodak, etc.).
> >
> >Sandy King
> >
> >
> >
> >
> >> A few days ago, I think I read on this list that two steps on the
> >>step wedge equals one stop. Is that correct? I am trying to figure
> >>out how to change my EI, because the shadows in my negatives shot at
> >>320 are about two steps too dense. Does that mean I'm over exposing
> >>one stop, approximately?
> >>
> >>Also: I am printing on Centennial POP. The brochure that came with
> >>it says to replenish the gold chloride toner after one 8x10 print. I
> >>cut my 8x10 sheets into four rectangles, so I thought that I could
> >>tone and fix four of these small prints, one after the other, before
> >>I had to replenish. But, that doesn't seem to be the case. After two
> >>prints, the toner is exhausted and doesn't replenish easily by
> >>adding 6mls of solution A and B, as advertised. I am wondering if I
> >>should hold all four prints in water and then tone them all at once
> >>in the gold toner? CAn you do that?
> >>
> >>--shannon
> >
> >
> >--
> >
>
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