tv wrote:
> Oh great, another variable, thanks...
There are only three variables that are significant, assuming you're not
going to play with (vary) your enlarger light source. These are encoded in
the term "FDP," which stands for Film, film Developer, and Paper.
Most anecdotal "trials" (called tests) of materials are wrong, because they
take a triple-variable situation and try to treat a single variable at a
time. In other words, let's say you use Film T, Developer D, and Paper M.
You decide to "test" Paper Y. So you buy some and print your negatives on
it. You note that highlights are more contrasty and harder to print. You
conclude, wrongly, that "Paper Y has harsh highlight contrast." It's wrong
because the FDP combination is what yields harsh highlight contrast--not
just the paper. In fact, if you also chose the right FD variables for Paper
Y, you could get low highlight contrast out of the FDP combination.
Phil Davis computerized all this in a marvelous but little-known program
called the Plotter/Matcher. In a nutshell, the program takes sensitometric
test data from films and papers and predicts the FDP match, showing it as
actual gradation plotted on a bar graph against a theoretical average. What
it allows is the radical compression of darkroom experimentation--the kind
of knowledge it would take a year of hard work in the darkroom to acquire
can be gained in an evening at the Plotter/Matcher, assuming you have all
the data. Phil sells the program but not the data (I have most of his).
Many people pick film, developer, and paper almost randomly, usually based
on rumored "properties" that may or may not be actual properties of the
material. Then, to some greater or lesser degree, they fight the natural
tendencies of that FDP combination in order to get the look in prints that
they want. They call this effortfulness "printing skill." <s>
An example: let's say Photographer Jones chooses T-Max 100 because he has
heard it is "high resolution" and he values "sharpness" in his prints. Then
he chooses Rodinal because he's heard that it has "high acutance." But then
he notices that prints of certain scenes all have a peculiar look--middle
values in the tonal range look curiously depressed (darker than they should
be). So he fools with papers, film development times, and burning and
dodging to try to get his prints to look right.
What has Photographer Jones done? First, he's chosen materials for the wrong
reasons. T-Max 100 has high resolution but relatively low local contrast and
no edge effects, so it often doesn't look "sharp" despite its high level of
detail. Second, Rodinal has decent acutance but no more than D-76 1:1, which
has no reputation for acutance in the conventional widsom. But the film
family curves show a definite dip in the film curves in the middle values,
meaning that on most papers, perfectly developed and printed pictures will
show a Zone V value as Zone IV. With proper highlights and proper shadows,
the middle values are too dark for Jones's taste. And since the tonal
properties have a much greater impact on the aesthetic effect he is trying
to achieve than he gives it credit for, he's not seeing the results he
wants. So he tweaks and frets, trying to counteract the natural properties
of the materials.
If he knew what he was doing, he could change one or more of the materials
to get the effect he wants. For example, if he was wedded to Rodinal, he
could switch to APX 100 for much greater actual acutance and edge sharpness.
If he wanted to stick with TMX, he could choose a better developer for it.
If he wanted to stick to his original FD combo, he could look for a paper
with exaggerated values in the middle of the tonal range, to counteract the
tonal properties of his FD choices.
If you choose the right FDP combination, printing is easy and the effects
you wish to achieve will be present in most of your prints. Some prints will
still take some effort and judgement to print, but no automatic merit
accrues to constant effortful struggling in the darkroom.
--Mike
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