Slides in the 50x50 format can be viewed by combining a pair of single slide viewers.
The lens' center should be about
65mm apart, the center of the viewing area about 61mm.
Specialist 3-D dealers carry purpose made viewers for both 41x101 and 2x50x50
format.
Projecting Stereo Slides
Slides residing in 41x101 mounts must be projected using a 3-D projector
(RBT).
Stereo slides mounted in the fifty-by-fifty format can be projected using
two conventional projectors with identical lenses and light source.
Each lens has its own polarizing filter to ensure that each eye only sees its own
half of the pair.
The images of points at infinity are arranged so that the left image is 65mm to
the left of the right image of the same point.
The projection screen must be a silver screen that preserves polarization.
An example is the Da-Lite Wonder-Lite screen.
