Re: direct positive

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From: Judy Seigel (jseigel@panix.com)
Date: 11/17/00-01:21:55 PM Z


On Fri, 17 Nov 2000, Tadeuz Jalocha wrote:

> Istvan, there goes a formula i found in the net.
> It gives me full speed with Kodak T-Max 100 ( i canīt say anything about
> other films because it's the only 4x5" B/W material i can get here )
> Border density: 3.0D
> Highlights: 0.1D
> What i like about this formula, is that it uses Hypo rather than the
> very messy thiocyanate.
> If you like a thiocyanate formula, try Kodak D-67 (Not D-76!)

CUT=====================================================

The basic ingredients of the reversal process Tadeuz cites are same as
Liam Lawless's process (dichromate, sulfuric, fixer, etc.), but Liam made
some crucial modifications and improvements -- the evolution and tweaking
of which evolved over several issues of Post-Factory (beginning with
"Eliminate the Interpositive" Issue #2).

Differences include:

1. Although various films could "work" with the process, Liam's tests
showed that Freestyle lith worked better than most - at half the price (or
less) and available in large sizes and rolls.

2. Liam's method enlarges from 35 mm, thereby rescuing us non-view-camera
types (although I assume could be done large format as well).

3. Even more to the point, Liam worked out a variable pre-flash to adjust
contrast of enlarged neg -- which can be as soft as needed for gum (eg. a
16 by 20 inch neg that printed marvelously with a density range of, I'm
not kidding, 0.55), to very high contrast for salt print or chrysotype,
density range whatever.

So you could make a large neg for gum and another for chrysotype from ONE
never-to-be-repeated 35 mm shot. Or make a couple of different densities
for gum.

I'm not sure if final version is in one issue, I think not. There's an
overview & update in Issue #3 & final tweak in #4. If Liam is willing &
folks are interested, I'll try to put a summary on web site for benighted
Post-Factoryless souls (although, needless to say, print story is easier
to follow and use, as shown by latest non-partisan scientific tracking
polls).

Judy

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| World Journal of Post-Factory Photography > "HOW-TO and WHY"
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