STEREO MOVIES 285finished positives were dyed in the complementary red and green.
When the film was projected and viewed with the color spec-
tacles, the images were not only seen in relief, but there were other
and unexpected results. The relief was entirely satisfactory, there
was more than a suggestion of natural color effect, and because of
the alternation in time, the color bombardment effect common to
still-color anaglyphs was missing. The films were surprisingly sat-
isfactory, and, except that they were positive-negative and re-
quired elaborate equipment, the system could be regarded as
highly successful.
In this chapter we have not emphasized the distinction between
motion-picture and still projection, for one very good reason.
Optical projection remains the same no matter whether the pro-
jected images are changed 20 times a second or 20 times
an hour. A system which will work with one, will, with a few ex-
ceptions, work with the other.
The outstanding exception is the motion-picture system just
described in which the right and left pictures are projected alter-
nately upon the screen. This is done simply to preserve the orig-
inal format of the picture. The stereoscopic control may be by
means of the polarized anaglyph, in which case the polarizers are
shifted in synchronism by an oscillating support, or a mechanical
shutter and an auxiliary synchronized shutter is held before the
eyes of each spectator so that each eye sees only its own picture.
Inasmuch as each eye sees only half of the projected pictures, it
is necessary to operate both camera and.projector at double nor-
mal speed to prevent flicker. For that reason if for no other, the
method may be considered obsolete as far as motion pictures are
concerned.
HOLLYWOOD GOES STEREO.-Many amateurs have asked, “If
stereo is practical for movies, why doesn’t Hollywood use it?” The
answer is that Hollywood is using it.
In August 1952, the writer had the privilege of seeing a preview
of portions of the Arch Oboler full color stereo production B’wani
Devil, and it was an experience long to be remembered.
The story, based upon a true incident of some years past in
British East Africa, offers plenty of opportunity for highly im-
pressive shots, but regardless of the subject matter the excellence