From: Judy Seigel (jseigel@panix.com)
Date: 03/10/02-02:55:41 AM Z
On Sat, 9 Mar 2002, Ed Buffaloe wrote:
> At first, when reading the Stevens and Norrish article (from the January
> 1937 issue of THE PHOTOGRAPHIC JOURNAL), I doubted halation took place in
> paper at all, as it is so often spoken of as a film phenomenon. Referring to
> Mees, S&N state that halation is caused by: "(1) Reflection of the light at
> the surface of the crystals, predominant with coarse-grained emulsions." and
> "(2) Diffraction at the edges of the crystals, predominant with fine-grained
> emulsions." If these are indeed the causes of halation, then I see no reason
> why halation should not also take place in a paper emulsion. But we must
> bear in mind that all of Stevens' and Norrish's tests were done with plates,
> not prints.
Ed, since there are (I assume) relatively coarse AND fine-grained
emulsions in "film" (or plates) as well, it isn't clear to me why this
should be defining.
> On page 21 of the JOURNAL, S&N state, "The production of these photographs
> [showing the Sabatier effect] is only made possible by the action of two
> separate but closely related facts. Firstly, the developed part of the
> plate is desensitized, and secondly this desensitization is extended for a
> short distance outside the image of the object." Their paper is concerned
> with the second, or so-called border effect. They do not address the cause
> of the first effect, desensitization of certain areas of the emulsion. This
> desensitization was not effectively addressed until William Jolly, et al.,
> published their first paper "An Explanation of the Sabatier Effect" in 1985.
The areas with the most development require the biggest push (ie., the
most re-exposure) to reverse... Is that really "desensitization" or maybe
just further to go? As noted, I've found Jolly tends to claim more than
he's proved & claims some things that aren't so -- And since I've had
reversal with NO development (as on the dye transfer matrix, which got a
short extra exposure before it ever went in the water, and totally
solarized), I don't see how that statement can be true (or even if true
some of the time, not defining).
> ....Any influence that soluble bromides may have on the effect
> is almost certainly caused by a local retardation of the development, which
> influence is removed by washing the plate before the second development."
> Stevens and Norrish are not trying to prove that no bromide reduction is
> taking place; rather that bromide is not a primary cause of Sabatier
> reversal, which is why they washed their test plates between the first and
> second developments. The fact is, with most developers, bromide *is*
> produced as a byproduct of development and it *does* have an inhibitory
> effect on development where it is present.
Oh criminy, that "almost certainly" is wishful thinking. Another thing
bothers me about this construction is that it totally ignores agitation.
I've done the process while agitating so wildly I don't see how bromide
could be doing anything to anyone it didn't do to everyone... And results
almost exactly the same as with almost no agitation at all.
And here's another point, dammit (is that OK Gord)? In the method of
solarizing I did (wet, through the negative) the mackie line is often
black, or black and white side by side as double (sometimes even triple)
lines. Or black for a space then abruptly changing to white, then back
again. (Examples on page 14, Issue #2.) So there goes the "bromide
restrainer" explanation. Restrainer would make it *white.* (Or white in a
print, clear in film.)
And besides: The WIDTH of the mackie line varies... are you ready? --
with the FOCUS. It's much wider where the focus is softest. It's thinnest
where focus is sharpest. NOTHING to do with bromide drag !
> ... On page
> 32, in their summation, they state: "It must be admitted, in view of the
> known restraining action of bromides and oxidation products, that the lines
> may on occasions be reinforced by this effect...."
"On occasions." Sure. But what about the *no* occasions ? Jolly is
making an over-arching theory that DOES NOT (excuse the expression)
COMPUTE. Sure, an edge effect can reinforce whatever, so can strength of
developer. Or exposure. Or time of development. As we know without a
theory.
> In my experience with *print* solarization, the presence of bromide
> definitely contributes to the formation of the reversed image. I encourage
> this most of the time by *not* washing my prints between the first and
> second development. On many occasions I see areas reversing in the tray
> during the second development--this is not desensitization of the emulsion
> but a destruction of image values created during the first development,
> which I believe could only be caused by bromides released during the second
> development.
But I've found so many OTHER variables... some of them quite loopy. And
how about the presence of silver for PHYSICAL development rather than
simply bromide? (Which if I recall correctly was Rainwater's theory.)
My tests showed BTW that with EVERYTHING exactly the same, time in
developer, exposure, etc.... but a well USED developer rather than a FRESH
developer, the quality of the print was infinitely better. So probably
there was extra bromide in the used developer but -- adding bromide to
the developer didn't do anything good.
BUT, has the process been tested with fresh developer with added silver?
I myself tested with added hydroquinone, which made the most gorgeous
solarizing (on a hot day) I ever got... but Jolly says the reason old
developer works best is because the hydroquinone is depleted. Is it any
wonder I don't trust the man?
And so forth.
Which is to say, quod erat non demonstrandum (Q E N D).
> Maybe the reason bromide papers generally work better than chloride papers
> is that they release bromides during development rather than chlorides
> (which can also act as a restrainer, but perhaps not quite so
What does "generally" have to do with it? And is it? Who says so? Is
there a study?
> efficaciously), though another reason may be that silver bromide grains are
> larger than silver chloride grains. I have found one so-called warm tone
> paper that solarizes well (though I have no idea the exact composition of
> its emulsion): Luminos Classic warm tone fiber.
Hi Ed: here's my theory (after more tests than should exist in this
universe): the variables are so subtle and complex, interacting like a
dysfunctional family... and NOT covered by any Jolly theory yet. I was
doing a different method but STILL getting reversal and mackie line...
that obeyed other rules (when it did rules). What use is a "theory" that
doesn't cover the phenomenon across the board ?
Besides... given the enormous subtlety of the process, which can only be
fine tuned through actual doing... what's more important, theory or
practice??? In fact if this were relevant, that is, if silver paper were
going to be around long enough for this to matter, I'd say Jolly's wrong
theories do more harm than good.
best,
Judy
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