TRICK WORK 235film is directly related to the distance from the camera, and nor-
mally, (because we cannot actually increase size with distance)
the size on the film is directly proportional to the distance.
However, the parallax positively defines the distance. If the
parallax is for ten feet and the image size is the diminutive one
normal for 20 feet, there is no confusion in perception. You will
simply see the miniature figure at a distance of ten feet. Parallax
is in full control of distance.
Therefore, the problem is simply that of moving the object
nearer the camera optically (by increasing parallax) while re-
taining the image size normal for the true distance (and this is
automatic). Such a thing is impossible in planar photography be-
cause we have no absolute standard of distance judgment, because
we have no definite perspective-distance perception and because
the planar photograph contains no parallax, the sole source of
definite distance perception.
However, let us return to the first part of this discussion where
it is stated that parallax is the sole distance determining factor in
stereo. Then the whole thing becomes quite clear. We leave
(Fig. 1) the model in the distance, and we obtain the small size
normal to that distance; at the same time we alter the parallax to
that of a nearby object. The stereo result combines the size nor-
mal to the original perspective, and shows the distance normal to
the parallax used.
Let me emphasize that this effect is not one which you have
to persuade yourself to see. It leaps to the eye, just as stereo relief
did when you first saw it. Almost always, the first question asked
when a space control shot is shown, is “How on earth did you do
it?” If the size reduction is only about half, and the model a
stranger, you will be asked where you found a midget to pose for
you.
But one of the most interesting forms of this control is when
a human figure between six to 12 inches tall has a place among
normally sized people. For example, with a little patience you can
show a man seated at a table and standing by his plate a girl
holding up a dinner knife as tall as she is!
You have seen the old, old combination shot in which a girl is
shown seated in a wineglass. It has been used over and over again
in publicity pictures, and the reaction of the laymen is a mild