Calibrating Cold War Aerial Spy Cameras
I love all things from the cold war. It is my historical obsession. Every time I’m in DC I hit the Spy Museum just to get a little recreated flavor from an era that I find to be one of the fascinating in American history.
Today the BLDG Blog ran a story about Optical Calibration Targets that were built in the 50s and 60s and used to calibrate aerial spy cameras. Basically they’re parking lot sized eye charts.
These symbols—like I-Ching trigrams for machines—are used as “a platform to test, calibrate, and focus aerial cameras traveling at different speeds and altitudes,” CLUI explains, similar to “an eye chart at the optometrist, where the smallest group of bars that can be resolved marks the limit of the resolution for the optical instrument that is being used.”
In our clever, digital era that is giving us almost daily images from Mars, it’s hard to imagine how integral these calibration targets were to developing high flying, film based spy cameras. It’s just fabulous.