Three-Dimensional Photography - Principles of Stereoscopy

STEREO PROJECTION 191

ice at the Stereo Guild laboratory has proven fully satisfactory.
The blower cooled lamps of 500 watts each provide brilliant illu-
mination for the 50 inch screen, and slides may be kept in the
carrier for as long as they need be for full examination without
visible injury.

M

Fig. 12-3. Simple mask for viewing stereograms.

Fig. 124. Mask box substituted for simple mask.

A carrying case for the projector and accessories is available, the
whole making a neat, compact outfit for either home or portable
use.
The Realist projector is a larger and heavier projector in which
sturdy machined controls and cut gears make for highest precision.
The slides are inserted right side up, at the top of the projector.
Pushing down upon a lever turns the carrier and brings the slide
into projection position with the first slide at the top ready for re-
moval. This carrier is machined to precision and maintains a con-
stant baseline.
The two lenses are built into a unit with all controls so that
lenses may be changed in a few seconds. This same removable unit
applies to the condensers and their glass Polaroid filters.