THE INVENTION OF THE CINEMA

The cinema is a complicated medium, and before it could be invented, several technological requirements had to be met. First scientists had to realize that the human eye will perceive motion if a series of slightly different images is placed before it in rapid succession-minimally, around 16 per second. During the 19th century, scientists explored this property of vision. Several optical toys were marketed that gave a illusion of movement by using a small number of drawings, each altered some what. In 1832, Belgian physicist Joseph Plateau and Austrian geometry professor Simon Stampfer independently created the optical device that came to be called the Phenakistoscope. A phenakistoscope‘s spinning disc of figures gives the illusion of movement when the viewer looks through a slot in the stationary disc. The Zoetrope, invented in 1833, contained a series of drawings on a narrow strip of paper inside a revolving drum. It was widely sold after 1867, along with other optical toys. Similar principles were later used in films, but in these toys, the same action was repeated over and over. A second technological requirement for the cinema was the capacity to project a rapid series of images on the surface. Since the 17th century, entertainers and educators had been using magic lanterns to project glass lantern slides, but there had been no way to flash large number of images fast enough to create the illusion of motion. A third prerequisite for the invention of the cinema was the ability to use photography to make successive pictures on a clear surface. The exposure time would have to be short enough to take sixteen or more frames in a single second Fourth, the cinema would require that photographs be printed on a base flexible enough to be passed through a camera rapidly. Strips or discs of glass could be used, but only a short series of images could be registered on them. In 1888, George Eastman devised a still camera that made photographs on rolls of sensitized paper. This camera, which he named the Kodak, simplified photography so that unskilled amateurs could take pictures. The next year Eastman introduced transparent celluloid roll film, creating a breakthrough in the move toward cinema. The film was intended for still cameras, but inventors could use the same flexible material in designing machines to take and project motion pictures. Fifth, and finally, experimenters needed to find a suitable intermittent mechanism for their cameras and projectors. In the camera, the strip of film had to stop briefly while light entered through the lens and exposed each frame; a shutter then covered the film as another frame moved into place. Similarly, in the projector, each frame stopped for an instant in the aperture while a beam of light projected it onto a screen; again a shutter passed behind the lens while the filmstrip moved. At least sixteen frames had to slide into place, stop, and move away each second. By the 1890s, all the technical conditions necessary for the cinema existed.