Australian movie director Phillipe Mora discovered two 3D films made by Nazi propagandists dating back to 1936, which were lost in a dark corner of the Berlin Federal Archive. To achieve the effect, the directors apparently held a prism in front of two lenses.
Mora was doing research for an upcoming documentary on Nazi cinema and propaganda when he discovered the 30 minute films. They had been previously ignored because they had been labled as "space films" instead of 3D ones. Oddly enough one film, a musical titled So Real You Can Touch It, featured shots of sizzling Bratwurst. [Variety via Wired]