I happened upon this tonight, which turned out to be a very interesting watch for any history buff.

It deals with war photography, reconnaissance, and technologies that allowed 3D or stereoscopic viewing of photos taken of German sites during WW2. Covered are aircraft, cameras, viewing and measuring equipment, V1 & V2 rockets, and examination of sites before and after bombings(dam busters, and carpet bombing images look crazy).

Worth a watch, and I believe PBS is free to residents of the USA, not sure about availability outside of states.

Main video, 3D Spies of WWII:

Companion site for more spy pictures of other areas:

The only negative thing about the video was the ridiculous over use of lensbaby style selective focus and the chromatic aberration that accompanies it. It's in practically every other shot, and is sickening.