The camera, I think, is going to be our best inspector.
John F. Kennedy
The President s brief, blunt remark was deliberate understatement. For months trie Cuban skies have belonged to U S photo planessoaring, diving, circling appearing and disappearing on swift, unexpected tangents. Diplomats may still argue about on-site inspection of Cuban missile bases, but the question is almost academic. Under the prying eyes of U S aerial cameras. Cuba lies as exposed as a nude in a swimming pool.
No spot on the long, narrow island is more than 40 miles from the sea; it is an easy if unwilling subject for high-flying U25 slanting their cameras on target from offshore. A single run along its spine rolls out the island on film like a topographical map Supersonic jets scooting in at low titude can roar over the horizon, photograph anything of interest, and be out to sea again in a total of five minutes.
Both high-and low-altitude photo work have improved spectacularly since World Har II. Cameras that work at 20-mile altitudesup where the U-2 flieshave 36 in.-100 in. focal lengths that turn their lenses into virtual telescopes. Some of them swing from side to side, reaching both horizons. But though the pictures show surprising clarity, their scale is still too small to illuminate fine details of objects on the ground. Clouds are another frustrating disadvantage; over humid Cuba they often spoil the view. High-Utitude photography serves best for surveying large areas that cannot be reached by fast, low-altitude dashes from friendly territory.
Low Passes. The most spectacular work is done by supersonic jets flying at palmtop level. This is always dangerous-today s jets are so fast that they may crash into a mountain before their pilots even sense trouble. During a low pass, everything blurs into meaningless streaks, like a fence a few feet from a speeding car Landmarks disappear. Objects to be photographed sweep under the plane and are gone in a fraction of a second.
Taking pictures under such conditions lor elaborate equipment. Low-level photo planes carry five or more cameras pointing ahead, astern, to each side and directly down. Since the pilot is too busy with flight controls to give the cameras my attention, they must advance their own film and give each frame the proper exposure for the prevailing light conditions. Pictures can be shot singly but the time over the target is so short that they are generally shot as quickly as possible often many times a second.
To do all these things correctly involves an enormous amount of optical, mechanical and electronic complication. Durino-low-level runs, the ground below sweeps past so fast that its image would smear on a stationary film, even during an exposure of one-thousandth of a second. A small computing device called an intervalometer must note the airplane's speed and altitude and figure out how fast the film must move to keep exact pace with the ground. Just before the shutter opens a vacuum sucks the film against a perforated plate that starts moving at the necessary speed. After the shutter has closed, the vacuum releases the film so a new frame can be advanced, and the plate snaps back to its starting position.