One way of receiving a stereoscopic impression through a microscope is by fixing an apparatus as directly as possible above the last lens of the microscopic objective, which divides the rays passing out and directs half into each eyepiece.
Very often such stereoscopic lenses, owing to faulty construction, give a false idea of space, ignoring the errors which are due to the alteration of the inter-pupillary distance and the visual angles belonging to the principal rays at the object-side (see Binocular Instruments).
The newest form of a stereoscopic microscope resembles the oldest in so far as two completely separate microscopes are used.
Binocular Instruments The stereoscopic microscope is the most suitable for finding out the space taken up by the separate parts of a preparation.
Abbe and C. Pulfrich), constructed the first stereoscopic range-finder suitable for practical use.
Binocular instruments should aid the natural spatial or stereoscopic vision, or make it possible if the eyes fail.
Efforts have been made of late years to improve the available methods of representing ground, especially in Switzerland, but the so-called stereoscopic or relief maps produced by F.