Which device allows viewing three-dimensional images?

• A. Stereopticon
• B. Stereoscope
• C. Holographic Viewer
• D. Anaglyph Glasses

Answer: (A)

Viewing depth in images comes from presenting two slightly different viewpoints to the eyes so the brain fuses them into a single perception of depth. A stereopticon is a projection device built to show stereoscopic slides—two images captured from slightly different angles—onto a screen. By projecting those paired images together for a viewer or audience, it creates a convincing sense of three-dimensional depth.

The stereoscope, while it can produce a 3D effect, is a handheld viewer that you look into to fuse two images on a card or print, so the depth comes from a single viewer rather than a projection to a screen. A holographic viewer displays true 3D holograms, which is a different technology from stereoscopic projection. Anaglyph glasses use color-filtered images to induce a 3D effect when viewed with the glasses, but again, that’s a separate method from projecting stereoscopic content for viewing.

So the stereopticon stands out as the device designed specifically to project and enable viewing three-dimensional imagery to an audience.