The Technology of Movies
Movies have been an important part of popular culture for about 100 years. Though essentially a photographic medium, movies have historically relied heavily on electrical, electronics and computer technologies.
In the era of silent films, cameras and projectors used electric motors to achieve constant film speed. In addition, electric lights were important in both filming and projecting. In the early years in the studios, arc floodlights and Cooper-Hewitt mercury-vapor tubes were most important. From the mid 1920s on, incandescent tungsten bulbs became common, both because brighter incandescent lights were newly available and because they did not produce the noticeable humming that arc lights did. The humming had not been a problem with silent films. After about 1940, tungsten floodlights with reflecting surfaces on the inside of the bulb behind the filament became common.Bell Labs produced Don Juan, a sound movie featuring John Barrymore. The movie premiered on 6 August 1926. Although there was no talking, the music and some saber clashes were synchronized to the action. A year later, The Jazz Singer, starring Al Jolson, did have spoken lines, and its success caused movie producers to rush to make sound movies.
Suddenly, electronics was vital to movie-making. Microphones converted sound to an electrical signal, which might be amplified or otherwise processed electronically. A photocell allowed the photographic soundtrack to be converted back to an electrical signal. And together with loudspeakers, amplifying tubes recreated the sound for the audience. Indeed, sound movies brought about the mass production of photocells, since they created the first large market for such tubes.
Electric lighting-- including neon and other colored lighting-- as well as projection systems and sound systems were vital to the success of the movie palaces of the late 1920s and the 1930s. Among the most famous were the Roxy Theater-- the “Cathedral of the Movie”-- at Seventh Avenue and 50th Street in New York City, and Sid Grauman’s Chinese Theatre in Hollywood.
The 1924 introduction of an editing machine called the Moviola facilitated movie production . This machine, which used a variable-speed electric motor and pedal control, was an innovation that made it much easier to splice footage together. As a result, movies became faster-paced, with a shorter average shot-length.
Multi-track sound was introduced in some cinemas for the first run of "Fantasia" in 1940, but thereafter was used little until stereophonic sound came in with CinemaScope and other widescreen formats in the 1950s. At about the same time, use of magnetic recording began. In addition to having higher fidelity than optical recording, it had the significant advantage of instant playback on the set. In the 1970s, Dolby noise reduction techniques came into use, both in movie-making and cinema presentation.
One of the most striking changes in movie-making in the past decade or two has come with using computer-generated imagery, beginning with Tron in 1982. Tron is the story of a video arcade owner and former programmer who becomes transported into the virtual world of the Master Control Program, the computer security system of a software company. The release of Toy Story in 1995, the first all-computer-generated feature movie, was another milestone.
A revolutionary change is currently underway, as digital electronics take over from photography as the underlying movie medium. An important early trial of digital film using a large-screen electronic projector, was Star Wars: The Phantom Menace in four Los Angeles cinemas.
Digital movies are attractive for several reasons: the movie can be stored and reproduced perfectly (no wear or degradation as with film stock); it can be distributed easily and inexpensively; and production costs for digital are lower than for celluloid techniques. However, the high cost of digital systems-- some digital projectors costs $150,000, for example-- still limits their use.