9.8.
ENLARGING
315
should be chosen and used consistently, so also should a single series of
relatively fast enlarging papers, limiting variation to the different contrast grades of one manufacturer.
Unfortunately, there is no standardization by different manufacturers
in the way different contrast grades of enlarging paper are designated.
Indeed, there is apt to be much variation in meaning in the products
of a single company. In selecting a paper, then, one wants to be sure
that a truly high-contrast grade is available. The Kodak Company's
Kodabromide F series, with five contrast grades (numbered in order of
increasing contrast from 1-5) serves well, and the number 5 paper is apt
to be used most. The Agfa Brovira 1 series has six contrast grades, and
their number 6 paper is substantially more contrasty than the Kodabromide F-5 paper, which is a decided advantage in some situations.
It is important to realize that contrast in a paper emulsion does not
have the same meaning as in the case of a negative. All papers will
produce nearly identical black tones and, of course, the "white" of these
is the paper itself. Thus, every paper possesses the full potential grayscale range, and proper printing spans the full range. Contrast in a
paper, therefore, is not a matter of the range from white to black. It is
rather a measure of the exposure required to produce the maximum
black as compared with the exposure needed to produce a just visible
tone. If the exposure needed to produce a maximum black is but four
or five times that needed to produce the first visible tone, the paper has
high contrast values, and is a "hard" paper suitable for printing "flat"
negatives. The differential may be thirty times or more in a "soft" low
contrast paper.
The implications of this are that the development of papers has relatively little effect on their contrast, since in all cases papers should be
developed long enough to produce maximum blacks. Contrast control
in the print must be governed by choice of paper contrast rather than by
developmental control.
However, excessive overexposure and consequent underdevelopment
will not produce a quality print. The full potential range of tonal values
only appears upon full development, and the print which is "pulled" will
lack these intermediate gray tones which add quality and, in electron
microscopy, give useful information quite above and beyond their aesthetic values [Figs. 38(a) and (b)]. Thus, the person without experience in
photographic enlarging must learn that he will get quality prints only if
he exposes correctly in the first place, and then develops fully.
ENLARGING
315
should be chosen and used consistently, so also should a single series of
relatively fast enlarging papers, limiting variation to the different contrast grades of one manufacturer.
Unfortunately, there is no standardization by different manufacturers
in the way different contrast grades of enlarging paper are designated.
Indeed, there is apt to be much variation in meaning in the products
of a single company. In selecting a paper, then, one wants to be sure
that a truly high-contrast grade is available. The Kodak Company's
Kodabromide F series, with five contrast grades (numbered in order of
increasing contrast from 1-5) serves well, and the number 5 paper is apt
to be used most. The Agfa Brovira 1 series has six contrast grades, and
their number 6 paper is substantially more contrasty than the Kodabromide F-5 paper, which is a decided advantage in some situations.
It is important to realize that contrast in a paper emulsion does not
have the same meaning as in the case of a negative. All papers will
produce nearly identical black tones and, of course, the "white" of these
is the paper itself. Thus, every paper possesses the full potential grayscale range, and proper printing spans the full range. Contrast in a
paper, therefore, is not a matter of the range from white to black. It is
rather a measure of the exposure required to produce the maximum
black as compared with the exposure needed to produce a just visible
tone. If the exposure needed to produce a maximum black is but four
or five times that needed to produce the first visible tone, the paper has
high contrast values, and is a "hard" paper suitable for printing "flat"
negatives. The differential may be thirty times or more in a "soft" low
contrast paper.
The implications of this are that the development of papers has relatively little effect on their contrast, since in all cases papers should be
developed long enough to produce maximum blacks. Contrast control
in the print must be governed by choice of paper contrast rather than by
developmental control.
However, excessive overexposure and consequent underdevelopment
will not produce a quality print. The full potential range of tonal values
only appears upon full development, and the print which is "pulled" will
lack these intermediate gray tones which add quality and, in electron
microscopy, give useful information quite above and beyond their aesthetic values [Figs. 38(a) and (b)]. Thus, the person without experience in
photographic enlarging must learn that he will get quality prints only if
he exposes correctly in the first place, and then develops fully.