Three-Dimensional Photography - Principles of Stereoscopy

272 THREE-DIMENSIONAL PHOTOGRAPHY

Before World War I, about 1910, Burke and James sold a stereo

reflector which had the first adjustment, and this is the reflector

used in the preliminary experiments of the Guild. Many amateurs

make their own, but if you have no skill with tools, you will surely

have, among your acquaintances, an amateur metalworker who

will be glad to make the attachment for you for a moderate sum.

We shall not give detailed working drawings, because there is a

-Lo

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Fig. 19-1. The Stereo reflector. This diagrammatic plan view shows no
mechanical supports, only optical elements. The two inner mirrors,
RI, and RI, set at 90°, join opposite ,the vertical diameter of camera
lens, L. At the right and left are the two outer mirrors, RO1 and RO,.
A1 and Ar indicate the axial rays for right and left, while LO, LI, RI
and RO indicate the approximate field limits. LI and RI indicate the
gradual convergence of these rays with distance.