Ryuji, what would you suggest adding to raise pH
slightly? I have been processing at 75 degrees, but will try higher.
The 'lith' film I have been using recently is a
Fuji scanner film HG HSA. I also use APHS but haven't tried with
LC-1.
Thanks very much for your help.
Subject: Re: LC-1 developer question
Date: Thu, 27 Mar 2008 13:41:17 -0400
So,
do I need to be using double the amount of sodium
sulphite or would the normal amount
of 60 grams work?
First of all, reducing sulfite may increase the
solubility of
Metol, but it may not be enough to solve your
problem.
All these will have to be determined
experimentally. The
amount of sodium sulfite has influence on the
development, and
it depends heavily on the type of the emulsion
being used.
The term "lith film" doesn't really describe
much, since the
term "lith" is commonly abused to mean high
contrast emulsions
for printing films in general, and there are a
very wide range
of such emulsions. Generally speaking, modern
printing
emulsions are monodisperse cubic AgBr emulsions
of 0.05 to 0.2
microns edge length, sulfur sensitized. Most
modern ones
probably make mostly surface image, and don't
really require
much sulfite to develop properly. But depending
on the nature
of latent image centers (determined largely by
chemical
sensitization and crystalline defects
introduced to the
crystals), varying the amount of sulfite may
affect the
sensitometric curves of the overall
system.
More immediate effects, however, is that the pH
of the
developer will likely change if you change the
sulfite content
without adjusting the pH, and this will have a
direct impact
on the developer activity and sensitometric
curves with
whatever emulsion you use.
In a low pH Metol developer, doubling the Metol
concentration
does not double the rate of development. If
your main
complaint is long development time, I suggest
you try raising
the processing temperature, raising pH
slightly, or
combination thereof.
--
Ryuji Suzuki
"Make something religious and people don't have
to deal with it, they
can say it's irrelevant." (Bob Dylan, Biograph
booklet, 1985)