I assume you are talking about Kodak Publication #5
"Kodak Professional Black-and-White Films", it is definitely a definitive
work. The publication went through many upgrades with the edition released
in the 80's and 90's. Although I prefer the early #2 edition, there were
improvements and modernization in the information over the earlier editions
of the 60's and 70's. Also the price jumped from below $3 to $10.95
"The Graphic representation of a typical photographic tone reproduction"
among other diagrams really clarifies the relationship between scene, lens,
film, and print.
Some factors that are harmful to photographic reproduction become apparent
with gross negative overexposure, they can difficult to print because of the
high density levels, also graininess increases, and sharpness decreases.
Kodak stated "three stops of over exposure should be considered the
practical limit". In the later editions Kodak deleted this statement.
I think what is wonderful about Black and white photography is the fact
that one can exploit the possibilities of the extreme latitude in exposure,
the wide range of films, development possibilities, choice of papers, the
possibility of manipulation during printing, and post treatments to produce
some really great images, or some real dogs. Who knows some dogs are mans
best friend.
Jonathan Ayers [mail1@xxxxxxxxxxxxxxxxx]
This is the right publication. I think I remember the
statement about overexposure but this disagrees with the work of
L.A.Jones on which much of Kodak's recommendations are based. Jones
and his associates researched both minimum exposure and latitude.
The original ASA speed measuring was based on this work. Jones'
method was originally adopted by Kodak for its internal use. For a
time, in the mid 1950's, they published Kodak speeds. These were
about four times the ASA speeds. Unfortunately, when the ASA
adopted this method they introduced a fudge factor that effectively
halved the film speed resulting in somewhat overly dense negatives.
This was corrected when the ASA later adopted a modified version of
the later DIN method. Jones, in his original work, was trying to
find the minimum exposure that would result in "excellent prints"
as judged by a large jury. He found that increased exposure up to
many stops did not make much difference but that even small
underexposure would degrade the tone rendition. Supposedly, Kodak
insisted that the ASA add the fudge factor to insure that amateurs
got an image even though the error for most cameras lies on the
overexposure side. Minimum exposure was the criteria because film
has somewhat better sharpness and finer grain for relatively low
densities. This is less so for modern films but still true.
