They won’t be showing these, though.

Unlike Hollywood’s 1950s 3-D movies, which used two projectors, the Nazi version used standard 35mm film cut in half into a split-screen. When it was projected, a prism would combine the two images.

Ironically, he first disclosed the find during the Berlinale, the Berlin film festival, this week, where filmmakers worldwide were rolling out 3-D movies.