I believe that 'Photography' as we think of it on this list has nothing to do
with a correct transformation of original tonal values in a sensitometric sense.
The conventional s-curve of silver halide emulsions is WRONG and it remains
wrong no matter how carefully one reads Ansel Adam's books or any other
publication on silver halide sensitometry. Human physiology works different. The
Weber-Fechner law applies to opticians but not to artists. Heinrich Kuehn showed
it clearly: Compared to human perception, silver gelatin emulsions give
unsufficient contrast in the shadows, place the mid-grey too low and again give
unsufficient contrast in the highlights. This drawback can be overcome by
complex negative masking or to some extent by using the developer DI 13 recently
mentioned on this list or - of course - by digital image processing. Kuehn at
his time developed a special two-negative system and a *syngraphic* film with
two coatings of different speed and contrast. How much the perception of a scene
can be improved by adapting a negative's characteristic curve to human
physiology can be seen through Charles Lewis' illustrations of his article in
the latest edition of RUNDBRIEF FOTOGRAFIE, which will appear next week.
But although a print could be improved in a physiological sense this way, this
alone wouldn't make it a piece of fine art. Not only must the subject matter and
composition follow artistic intention, but also the tonal values must be
'organized' to support the artist's objective and help the viewer to get the
'right' feeling. The zone system offers a certain control but only allows for
compressing and decompressing the whole scale of tones. Making a (long scale)
negative according to the sheduled processes' needs is not a value by itself -
it may help not to loose texture in an important part of the image if you don't
know at the beginning how you'll print it, but I would regard this as a
compromise. A good photographer should know while viewing the original scene how
the print should look like and probably will decide for a much shorter scale of
tones in the neg. And then it's easier to organize 10 values than 256 or even
one million... Under the best circumstances, this organisation of tonal values
is done due to a subjective selection of tones (previsualisation) according to
physiological rules, experience and artistic intuition. At least this is what
painters do and what straight silver bromide printing cannot.
Platinum, salted paper, cyanotype and similar reduce the number of tones by
20-30% compared to silver gelatin: If I concentrate on good separation in a
certain group of tones, I may therefore loose separation in another group. Gum;
oil, bromoil and esp. their transfers as well as photogravure additionally allow
for individuel influence on certain groups of tonal values. Deciding which
values to cut off for which value's benefit may be difficult. But there lies the
secret why some platinums for instance are superior to some silver gelatin
prints. I remember printing a forest scene during a heavy rain against the light
in pure platinum. Although the neg showed texture in the trunks and roots I
decided to let them disappear in the dark for the benefit of the glittering
rain. The photographer liked this approach much more than the 'perfect' silver
print he had made himself before.
Some time ago somebody on this list complained about the lack of tones in Irving
Penn's platinum prints. If Penn had wanted to show more, he had made a silver
gelatin print... The same with Demachy's or Kuehn's gums... And who thinks Paul
Strand printed too dark (either in silver or platinum) hasn't understood him.
Controlled reducing and this way abstracting (hiding things) gives way to
interpretation and allows accessing the image. It creates more tension then
presenting everything on a silver tablet: it makes curious. And this is what the
alt.processes can give us to a much wider extent than silver printing. Ron
Silvers wrote about papers, but I think 'papers' could easily be replaced by
'processes' : <I believe different types of papers bring us to recognize
different kinds responsive sentiments (feelings) to photographs.>
For the reasons above I am somewhat sceptical if people try to find or ask for
the 'perfect' formula or working practice. Didn't the silver gelatin industry
demonstrate sufficiently what happens once the 'perfect' material has been
found? Every 'imperfect' material disappeared, leaving a few almost
indistinguishable bromide papers and disappointed photographers behind... If one
day somebody had found the platinum paper with a Dmax of 2.0 or the idiot-safe
gum process, what would it be good for? To pass over it I assume.
Klaus Pollmeier