Stereoviews

Stereoviews are paired photographs or images that are slightly offset from one another so that, when viewed through a stereoscope or similar device, they produce the illusion of three-dimensional depth. Each image is intended for a specific eye, and the brain fuses the two views into a single, immersive scene.

The concept originated in the early 19th century with the development of the stereoscope. Charles Wheatstone described the principle in 1838, and soon after photographers began producing stereo pairs for public entertainment and education. By the late 19th and early 20th centuries, stereoview cards—flat cards bearing two side-by-side images—became a popular mass medium, covering travel, landscapes, city scenes, celebrities, and events. Publishers such as Underwood & Underwood and numerous studios produced thousands of titles, making stereoviews a staple of visual culture during the heyday of the photo card.

Formats and viewing devices vary. Traditional stereoviews are viewed with a mechanical or handheld stereoscope that positions each image for the corresponding eye and magnifies the scene. Some viewers rely on mirrors, lenses, or prisms to create the depth effect. In the mid-20th century, consumer formats like the View-Master used color photo reels to present stereoscopic images to children and families, without requiring a separate box or card. Modern versions include digital stereoscopic images and 3D photography, which use similar principles with computer processing and display hardware.

Stereoviews have influenced fields ranging from education and collecting to entertainment and virtual reality, illustrating how binocular vision can be leveraged to convey depth and realism in flat media.