As far as the final density range of the lith film, yes, you can almost get
any range that you want. If you want real low density range, you might need to
mix your own formula because too much dilution might cause some problems.
The real problem is with the exposure range of the lith film. If your original
negative has a long range, you will lose highligh (or shadows or both)
depending on which part of the curve you place your exposure. This losing of
scale might or might not be a problem in the final image. If you are careful
in placing the tone, you might be able to place the important highlights and
important shadows in the linear zone.
If your original negative has a long range and you do need such a long range,
it is best to make the interpositive on a true continuous-tone negative (as
Sandy also pointed out). That way you don't compress the tone, and you can
process the continous-tone negative to the range you want and then enlarge the
negative on lith film.
About half a year ago I question the need of pmk processing just to get the
density range needed (although I ask/said it too strongly, I admit and
apologize). With Dektol alone, I can *easily* get to the density of 2.7 with
1+10 dilution. I certainly can get higher with less dilution. The density of
2.7 is much higher than needed in Pt/Pd printing, I believe.
There was one worker who said that he was using some special (or outdated?)
film which he could not get the density he needed. With PMK the yellow
staining (which blocks UV light) allowed him to achieve the high density. That
I think is a very clever use of PMK. However, with lith film, the film itself
is already capable of achieving high density (it is used in graphic arts where
you can process it to density of 3.5 or higher!) So why does one need to use
special developer to achieve the density? My problem has been lowering the
density range, not increasing.
I guess I'd better stop. Some things are difficult to describe without showing
all the charts, figures, etc. so please check out my future article in the
journal. Meanwhile, if you have any specific question, feel free to ask.
Dave S