INTRODUCTION xisauctions for making even more elaborate shifting bases which
may be made at home.
Black-and-white stereo films may be processed by any com-
mercial finisher if you choose, but in that case you will have to
do the work of mounting for stereo viewing. On the whole it will
be found more satisfactory if you do all of the processing for
yourself. When color is involved, few amateurs will care to at-
tempt the processing.
Experienced stereographers often dispense with the viewer,
but the beginner will find it extremely difficult to obtain correct
visual fusion without it. The viewer need be nothing more elab-
orate than two of the simple magnifiers obtainable at most nov-
elty and stationery stores. These are attached to one another so
that the centers of the lenses are about two and a quarter inches
apart. Viewed through these lenses, the stereogram will fuse into
a single, solid picture.
Later you will want a better viewer and a better camera, but
these simple pieces of apparatus, to be more fully described later,
are the only actual essentials in addition to normal photographic
equipment.
The opinion has become widespread that some special knowl-
edge or experience is essential for making stereograms. This is
wholly erroneous. Anyone who can make a photograph can make
a stereogram. If his skill is such that he makes a poor photograph
he will make a poor stereogram, and if he can make a good
photograph he can make a good stereogram. The only thing in-
volved here is that stereoscopy enhances the effectiveness of any
photograph, so if it is poor it seems very poor indeed in stereo,
but if it is good then in stereo it becomes excellent.
Curiously enough, the very essence of nonentity in the form of
black shadows and white highlights forms a considerable part of
the modern planar photograph. Such elements seriously detract
from the quality of the stereogram. Hence stereographic tech-
nique must be such that they are avoided. Ordinarily the stereo-
graphic negative will be better if the normal exposure is increased
and the negative development decreased.
The stereographic composition is not limited to one plane,
therefore classic pictorial composition loses much of its force
when applied to the stereogram, and often that which produces