Graphics Reference
In-Depth Information
The constraints of metal blocks yielded
to the elasticity of photographic processes,
and innovative designers rapidly explored
new possibilities. The lens system permitted
photographic distortion. Characters could be
expanded, condensed, italicized, and even
backslanted (Fig.
7-14
). The tremendous
expense of introducing new metal typefaces,
requiring punches, cast letters, and matrices,
was replaced by the cost of one economical
film font. As a result, many new display
typefaces—as well as revivals of earlier
styles that were no longer available—were
introduced at a rapid pace.
7-12
Components
of a typical display
phototypesetter.
Keyboard phototypesetters
Keyboard phototypesetters were introduced
in 1950. Two major types of phototypesetting
systems (Fig.
7-15
) were developed: photo-
optical and photo-scanning systems. They
have the same basic components (Fig.
7-16
);
the primary difference is how the photo paper
or film is exposed.
Photo-optical systems store characters
as a master font on film disks, drums,
grids, or strips. The letters, numbers, and
other symbols in the text are input on a
keyboard. A typical film disk or drum spins
at several thousand revolutions a minute,
and a computer controls the exposure of light
through the negative characters and a lens,
onto light-sensitive paper or film. At the same
time, the computer advances the paper or film
in a transport device, moving it forward by the
set width of the previously exposed character
and into position for the next character to be
exposed. Different lenses are used for different
magnifications, so the typesetter can set
different sizes of type. The computer makes
very precise adjustments in spacing for the
specific type size, and increases interletter
and interword spacing when setting justified
text columns. These systems are capable of
setting hundreds of characters per minute.
Typography
Typography
Typography
Typography
7-13
Unlike hand composition, where every letter is
cast on a block of metal and cannot easily be kerned,
display photo-type interletter spacing is visually
controlled by the operator and can be set wide,
normal, tight, or even touching.
7-14
Photographic distortion permitted by the lens
system allows characters to be normal, expanded,
condensed, backslanted, and italic (top to bottom).
