These viewfinders mimic a much older object—the stereoscope. An invention of the nineteenth century, the stereoscope plays on our binocular vision to produce an exciting viewing experience. Two images—a left eye and right eye view of the same scene—are printed on a stereograph card, and when viewed through the stereoscope, appear as a single 3D image. The first stereoscope was debuted at the Great Exhibition of 1851, a world’s fair held in London, and quickly became popular on both sides of the Atlantic. Just five years later, more than a half million stereoscopes had been sold.
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Stereoscope in the library, Gibson House Museum |