One of the easiest
stereoscopes to make is one using a single mirror. 2 computer screens,
radiograph viewing boxes, or pictures are placed at 45o to each
other with one image laterally reversed. A carefully sized mirror
is then placed on the plane between the two images - this superimposes the
images optically in the right viewing position. If at all possible,
a front-silvered mirror should be used to eliminate ghosting.