Re: physical developers

From: Richard Knoppow <dickburk@ix.netcom.com>
Subject: Re: physical developers
Date: Mon, 23 Aug 2004 22:51:15 -0700 (GMT-07:00)

> It is likely that some fine grain chemical developers have some
> contribution from solution physical development.

I doubt it. If you mean stuff like p-phenylenediamine, maybe, but not
developers like D-76 or D-23. Or D-25 for that matter. Haist did some
studies on antisludging/antiplating agents to use for highly solvent
monobath formulae. Some agent increased or decreased sharpness, some
agent increased or decreased granularity. All combinations were
found. Of course some agent inhibited development and/or fixation
altogether. This reconciled the views about fine grain
developers. Simply, those developers with high solvency but low
physical development are more likely to produce finer grains if
everything else is same. Research on developer formulations went out
of fashion in 1970's or so, so I don't know if later science brought
this issue to resolution, but in my experience of making practical
developer solutions, I've encountered few or no cases that
contradicted with this view.

Probably the most useful application of physical development today is
intensification of images, such as weak lantern slides (before toning)
or underdeveloped plates. When I use commercial material, I never felt
silver intensifier a necessary standby, but since my emulsions have
more variables and results are not as predictable, I think silver
intensifier will be worth playing around with. In particular, my paper
comes in one fixed grade, and not much material is available for
making test strips. What else can I do?

--
Ryuji Suzuki
"You have to realize that junk is not the problem in and of itself.
Junk is the symptom, not the problem."
(Bob Dylan 1971; source: No Direction Home by Robert Shelton)