Stunning Stereoviews: Historical Photos Show Past in 3D

The opportunity to catch a glimpse at life in a long-ago era in 3D is rare indeed, but thanks to the stereoviews taken by photographer T. Enami, Meiji Japan in the early 1900s momentarily appears vivid and immediate.
In traditional stereoscopic photography, a three-dimensional illusion is created from a pair of 2-D photographs that represent two slightly different perspectives of the same object or scene. The deviation between the two photographs is similar to the perspectives that both eyes naturally receive in binocular vision.
Such images are normally viewed in 3-D using a stereoscope, but ‘freeviewing’ is also possible, with a process that involves putting one’s eyes directly over the images and slowly backing away while focusing on the single merged, out-of-focus picture that appears.