Three-Dimensional Photography - Principles of Stereoscopy

THE STEREOSCOPE 29

of a cardboard disc and viewed in succession by moving a lever
in the device, Despite the absence of adjustments, the Viewmaster
is a highly satisfactory stereoscope.

Fig. 3-1. The Sawyer Viewmaster.

THE REALIST VIEWER (Fig. 3-2) companion to the camera of
the same name, is of polished black plastic material and contains
its own battery and lamp, thus making the unit self-contained
and ready for use regardless of external light conditions. This has
long been recognized as the desirable method of stereo viewing.
For home use a low voltage transformer is available so the light
can be maintained at a more uniform level, a most important
factor in color viewing.

Fig. 3-2. Stereo Realist viewer. Self-illuminated,

with focusing and interpupillary adjustments.