Stereophotoduplicon

Stereoscopic images are side-by-side images that appear 3d when viewed in a viewer. The Google Cardboard stuff works in this manner.

This is a device that displays the same image twice with an offset such that a camera could take a single picture. You only get half of your camera's sensor (since the splitter is using two images in one shot), but it is easy and convenient to play around with taking 3d pictures or making videos.

This was originally designed in 1894 by Theodore Brown, and he