Word: hologram
(lookup in dictionary)
(lookup stats)
Dates: during 1966-1966
Sort By: most recent first
(reverse)
Holography produces no familiar photographic negative or print. But when light is directed upon a holographic negative-or hologram-its smudgy and apparently meaningless patterns of concentric circles and parallel lines become a window through which a viewer sees the scene that was photographed. By moving his head from side to side, he can look through that window at different angles and change the perspective of the three-dimensional view; he can look around an object in the foreground to see what is behind it, just as if he were examining the actual scene...
...produce a hologram, light from a laser is split into two beams, one of which is directed by a mirror onto a sheet of photographic film. The other beam is used to illuminate the subject. When the laser light hits the subject, it is scattered by the irregular surface and reflected back toward the film. As a result, many of the reflected light waves are jumbled and out of phase both with each other and with the light from the undisturbed beam reflected by the mirror. When the light waves from subject and mirror are reunited at the surface...
Holography Handicaps. To pluck a hologram and release its light waves, a laser beam is passed through it. As the laser beam hits the hologram's interference pattern, it is diffracted into light waves that duplicate those that were reflected from the subject. The viewer sees the subject of the picture in three dimensions, apparently suspended behind the hologram at the same distance it was from the sheet of film...