NOVA is touting a new special, the "3D Spies of WWII." While the actual technique they used is still amazing, calling it "3D" is kind of silly. The technique places two pictures taken from slightly different angles next to each other. When viewed close up, the brain interprets the image from one picture (going to one eye) and the image from the other picture as a sort of three dimensional image. It's something that field geologists have used for decades to get a better idea of what the landscape is like. Particularly because hills and depressions show up more easily. But the title is simply a re-branding of a centuries-old technology. It kind of annoys me, but at the same time I understand that "stereoscope" and "3D" make use of the same visual illusion, "3D" has more cultural relevance today. It's one of those connotation versus denotation issues. While they mean the same basic thing in fairly specific terms, they convey a fairly different sense of relative meaning.
One could do some interesting optics analysis to demonstrate how a British intelligence service person could estimate the height of a V2 rocket based on a simple pair of photographs.