On Sat, 8 Jun 96, he wrote: <Therefore, in recording a scene on film, the
negative exposed and processed for a silver print will have to have more tonal
compression than one made for printing on platinum. And, once you've compressed
the scene, you can never get back that lost tonal seperation no matter what the
density range of your paper is. So it doesn't matter that the silver paper is
capable of a higher Dmax, because you've already lost the tonal seperation in
the neg.>
This certainly is wrong and unlogical, as it woud mean that copying/enlarging
negatives and adapting contrast to the amount needed by a certain process would
imply a loss of tones. What would then a Goldberg diagram be good for? As long
as you are working on the straight part of the curve, the only thing one could
expect is a loss of sharpness. But nobody hangs negatives on the wall.
As long as the gradation of the negative and the positive match, the amount of
perceivable tones is determined by the Dmax of the positive print, as you can
pack more of the minimum differences (required by the eye to separate one tone
from the next) into a 2.0 space than into a 1.4 density range. That platinum
needs a dD of 1.8 and a silver print 1.2 doesn't mean, that there are more tones
in the platinum. In fact there will be less tones perceivable due to the lower
Dmax. Or, as Peter Marshall pointed out: <The number of tones you get is largely
a function of the density range of the print medium (with some allowance for its
surface, the illumination you use to view it etc.)>
But, as was said allready, the total amount of different tones is only worth
discussing for "density transmitters" and not necessarily for artists...
Pete Marshal wrote: <For what it is worth I don't feel that platinum gives an
apparently denser black than some silver materials (although carbon does.) All
these materials can give an adequate black which is what really matters.>
That's it. It must be adequate, no matter what number hides behind its Dmax.
On Fri, 7 Jun 96, Terry wrote:
<The question I have been asking is how wide a brightness range can we perceive
if we are at a single point and do not move from it. No matter how much we scan,
if an area is on zone 9 and the area next to it is on zone 1 and we are looking
at them both at the same time we will not be able to see the detail in zone 1
although both can be recorded on film> A day later you say: <I say that a scene,
at one time from one point, can recorded on film with the film recording far
more than we can see because we do not have the opportunity for the eye to scan
and adjust and we are not physically capable of perceiving contiguous
brightnesses that differ by more than about seven stops.>
Terry, are you crosse-eyed? How can you look at two details at the same time? As
soon as you are switching from one to the next detail (scanning...), your eyes
adapt to its brightness and the longer you concentrate on it, the more details
you perceive. Only if your eyes rest on that single detail, your point is
correct: Then high or low densities in the neighbourhood will disappear in
brightness or darkness. And certainly you are right considering that as the
interesting point: Our decision what to show and how to show it. I assume that's
what you mean when you say:
< That is just one of the points. If the printer is presenting more than we can
see of the scene the viewer, he is imposing his own view of the syntax on the
viewer, and it is a distortion.>
No, it is not a distortion, it is just a physically correct "density
transmission" but probably not an interesting "density interpretation" (which
would be distortion in a positive sense).
<The real point remains that platinum can accept more of the scene, as we see
it, directly from the negative than can the silver gelatine print.> Certainly
wrong regarding physics, but definitely true as an artists statement. "As we see
it?" How do we see? Some of the seeming differences in the previous discussion
were due to the definition of "seeing", I assume (or the lack of it.) Wether
seeing is "density transmission " or "density translation (interpretation)" Of
course it's both, for each individual (or each photographic problem) to a
different extent. The only criterion we have to judge the way a photographer had
chosen to get out of that dilemma: Does form follow function? Ansel Adams' or
Jeff Wall's work as single coat gums? Demachy's dancers as perfect silver
bromides?
I enjoyed this discussion, which (at least to me;-)) claryfied things. Would
those who took part in it agree to the consensus: "Sensitometry is a perfect
tool but not the key...?"
Klaus Pollmeier
p.s.: Judy asked: <Just one other point: what's "the original scene" got to do
with it?> A too philosophical quesion for me... ;-)