From: Eric Neilsen (e.neilsen@worldnet.att.net)
Date: 06/25/00-05:09:20 PM Z
Judy Seigel wrote:
> On Sun, 25 Jun 2000, Eric Neilsen wrote:
> > ... The combinations of chemicals sources,
> > concentrations,
> > light sources, humidity ranges and paper give a big change in speed and
> > contrast. It could be done for a specific user and/or set of variables
> > but not
> > all pt/pd printers work the same. DOP, POP, DOP/POP. Jeffrey had it
> > right.
> > Learn by seeing and adjusting your eyes to your process. Absolutes work
> > in a
> > closed environment but not so well in pt/pd printing.
> >
> > "i.e.drops [recommended] " of what? contrast agent(s)? Pt vs. Pd ? FO
> > to Pt/Pd?
> > ?????
>
> Extrapolating from cyanotype, which I suspect is more similar to pt/pd
> than is generally credited (except of course for aura and $$$$), there are
> even more variables, such as double coating, which makes an enormous
> difference under SOME conditions, the *particular* lot of a given paper,
> whether the mfr sized it summer or winter, and did you say light source?
> I've found denser blue with bulbs X than Y. Etc.
>
Double coating can also make a big difference in noble printing as well.
>
> But anyway Eric, if you get "absolutes" to work in YOUR environment you're
> a better man than I am... they hardly don't ever around here.
The absolute that works is final inspection. I don't waste my time printing
step scales before I begin printing each day. Testing of steps scales
(density ranges) help you get close to understanding what's possible, but
until you pull a print on the paper that you have chosen, you really don't
know if you need to make adjustments. However, If something worked at 4' 15"
one day, it will be very close next week or next year and by then I may choose
to present a print differently. The chemistry most certainly will be different
a year from now. When you make your living printing your own work as well as
work of others, it pays to get very close day in and day out with certain
combinations of additives.
> But puts me
> in mind of the gentleman in a workshop who was mightily, um, peeved, and
> obviously skeptical of my expertise, when I couldn't give him a "curve"
> for gum of precise relationship between exposure and density. (Turned out
> he was an actuary.)
>
> Judy
There will always be those that want an absolute value defined for them. They
have yet to learn that, in the world of art and science known as photography,
they will be the one that ultimately makes that definition and it will be
absolutely their own.
So how does one measure density range? how ever they want!
-- Eric J. Neilsen 4101 Commerce Street, Suite #9 Dallas, TX 75226 214-827-8301 http://e.neilsen.home.att.net http://www.ericneilsenphotography.com
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