Re: Reversal processing for enlarged negatives

From: Loris Medici <loris_medici@yahoo.com>
Subject: RE: Reversal processing for enlarged negatives
Date: Wed, 24 Mar 2004 15:32:23 +0200

> Well, I don't have any idea! I just know it's an ortho-litho film (old
> type) that one can develop in standard A+B developer. Will test,
> calibrate and start to use it... BTW is there anyone who knows if there
> are any difference between old type film (developed in A+B solution) and
> the new type film (developed in Rapid Access solutions)? Can I
> substitute old type with new type film for making enlarged negatives by
> reversal processing?

I don't have any industrial experience so this is based on what I read
from people in the industry, patent literature, etc. combined with my
limited ability to reverse analyze.

Classic lithographic films that are processed in hydroquinone-only
developers are usually silver chlorobromide (higher proportion of
chloride than bromide), with at most a trace amount of iodide, with
cadmium or some other contrast enhancing agent, and other metal salts
such as rhodium, iridium, iron salt, and usually sulfur
sensitized. Silver to gelatin ratio has to be relatively large (less
gelatin). All sorts of additives are patented to the extent that I
don't know what works and what doesn't. These have to be mostly AgCl
because hydroquinone has difficulty developing AgBr.

Newer types are typically faster, and more like classic line films or
typesetting films in terms of CI and Dmax. These are developed in
phenidone-hydroquinone or phenidone-ascorbate developers, and such a
developer can develop pretty much anything so these films can use a
very wide range of techniques to improve contrast, but sometimes such
an improvement requires specifically matched developer. All sorts of
stuff are patented and published, with some overlap with stuff used
for pictorial negative films.

In terms of reversal processing, I think the results would be widely
variable... but the most important variable is the amount of
thiocyanate added to the first developer (and exposure, of course).

> I don't think they're stocking D19 here; you can't buy even "Xtol" from
> Kodak Turkey! They simply don't import it (we buy it from parallel
> importers).

Too bad... If mixing D-19 is a trouble, I'd use Dektol stock strength.

--
Ryuji Suzuki
"All the truth in the world adds up to one big lie." (Bob Dylan 2000)