Hi ng,
I'm just begining to dive into the photographic process, so my
practical experience is still scarse. - I try to figure out the basics
in a theoretical way first. In case of the negative/positive process
(both b&w and color) there is the relationship of contrast and gamma
and I simply can't get that into my head, no matter how much I read
and think (maybe I read the wrong papers?!).
One thing is that negative gamma and print gamma should combine to 1
if the contrast reproduction should match the scene (or 1,1/1,2 if you
take into account that most people prefer a slightly exaggerated
contrast of the midrange values).
If that=B4s true and the negative is developed to a kind of normal gamma
of 0,6, print gamma must be about 1,7. In the case of b&w contrast
must be balanced between the negative and the print if contrast is to
be reproduced correct. So if the neg has, say, 1,3 log units it must
be printed on a paper that is also capable of 1,3 log units. Not more,
not less. So if you chose the paper grade according to the neg
contrast, doesn=B4t that mean that you might have to chose a grade that
leads to a gamma which doesn=B4t combine to 1 with the neg?
Another thing that give me headaches in the same context are color
prints. In the case of the color reproduction chain, the negative is
normally developed to a gamma of about 0,6 and most papers have a
gamma of more than 2,5, so the combined gamma is 1,5. - So how does
that work? And why are color papers not available in different grades
to balance with the neg contrast?
You see I=B4m kind of lost with those concepts and I really hope that
someone could shed some light on them to show me what=B4s going on.
Monica Schulz
|
