CHAPTER 5MOUNTING, TRANSPOSITION AND SPACINGo FAR WE HAVE CONSIDERED only the essential factors involved
S in making the stereogram, but there are some factors involv-
ing the relationships of the two images which must be considered.
TRANSPOSITIoN.-One of the most important things the stereo
beginner must learn is correct transposition. To do this it is neces-
sary to know why the operation is required, what the operation
actually consists of, and what happens if it is ignored.
Fig. 5-1.Figure 5-1 is a plan view of a stereo field as seen by the two eyes
L and R. The field contains the objects A, B, C and D as well as
an object at an infinite distance. In front of the eyes lies the
picture plane p-$. The intercept of the ray path in this plane
from any point in the field determines the perspective of the field,
and, when viewing the stereogram, the stereo images actually
occupy this field whence they are visually projected to their cor-
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