APH and LC-1 (Re: Film)

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FotoDave@aol.com
Date: 02/05/00-10:21:01 AM Z


> but for positive/negative on the (very cheap!) lith you can
> get very good control with Dave Soemarko's method as outlined P-F #2. And
> if it's too much trouble to mix his low-contrast developer, he says (and
> reports are) you can do more or less as well with D-76.

Hi Judy and all,

Yes, the more I use APH the more I love it! The most important thing is to
make the right interpositive which should have
   - low contrast so that tones will not be compressed when making the
negative.
   - all tones placed in the *linear* region

LC-1 with dilution 2:3:5 and development of 5-8 minutes with constants
agitation will give that.

Once you get the right interpositive, control for negative is VERY easy. One
can use LC-1 with much less dilution (e.g. stock A only) or D76 or Dektol.
Since the contrast of the interpositive is low, development is much less
sensitive with time / agitation/ temperature, and one can get high Dmax and
neutral tone with lith film easily.

For those who want more control, the non-linearity of lith film (the toe and
shoulder parts) can be utilized. For example, you might deliberatedly want
the shadow to have higher contrast and highlights lower-contrast (expose the
interpos less to use the toe) or you might want it the other way around
(expose more to use the shoulder). Thus one can select the curve to use just
like in a copy negative.

As for D-76, it works basically the same with diluted Dektol (final effect is
similar) except that it works slower so that one can develop for longer for
better control; but D-76 is still pretty active so while it will lower
density range it won't open up the exposure range (the number of steps that
it can separte). If the original negative is about normal or low contrast,
one might find a dilution and *perfect* exposure to make it work. Otherwise
LC-1 is easier.

When I wrote the article on lith film, I was interested in presenting the
method of using bisulfite to control contrast because it can be useful for
other films as well. I more or less assume that those interested can use the
information and find the combination (dilution/time for interpos,
dilution/time for negatives) themselves, but it looks like some people like
to have a complete working method presented, so I am writing down a complete
procedure for going from negative to positive. My method now involves making
a step tablet test in the beginning of the session, and with the help of an
exposure meter or densitometer (or experience), one can make *all* the
interpositive right w/o further testing (well, maybe *at most* one test)!

Dave Soemarko

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