Intermediate film system
Encyclopedia
The intermediate film system was a television
process in which motion picture film
was processed almost immediately after it was exposed in a camera, then scanned by a television scanner, and transmitted over the air. This system was used principally in Britain
and Germany
where television cameras were not sensitive enough to use reflected light, but could transmit a suitable image when a bright light was shown through motion picture film directly into the camera lens. John Logie Baird
began developing the process in 1932, borrowing the idea from his licensees in Germany, where it was demonstrated by Fernseh
AG in 1932 and used for broadcasting in 1934. The BBC
used Baird's version of the process during the first three months of its high definition television service from November 1936 through January 1937, and German television
used it during broadcasts of the 1936 Summer Olympics
. In both cases, intermediate film cameras alternated with newly introduced direct television cameras.
The exposed film, either 35mm or 17.5mm (35mm split in half, to save expense), travelled in a continuous band from the camera, usually atop a remote broadcast vehicle, into a machine that developed and fixed the image. The film was then run through a flying spot scanner (so called because it moved a focused beam of light back and forth across the image), and electronically converted from a negative to a positive image. Depending on the equipment, the time from camera to scanner could be a minute or less. An optical soundtrack
was recorded onto the film, between the perforations and the edge of the film, at the same time the image was taken to keep the sound and image in synchronization.
The Intermediate film system, with its expensive film usage and relatively immobile cameras, did have the advantage that it left a filmed record of the programme which could be rerun at a different time, with a better image quality than the later kinescope
films, which were shot from a video monitor.
Television tubes developed by Farnsworth and Zworykin
in the United States, and by E.M.I. in England, with much higher sensitivity to light, made the intermediate film system obsolete by 1937.
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
process in which motion picture film
Film stock
Film stock is photographic film on which filmmaking of motion pictures are shot and reproduced. The equivalent in television production is video tape.-1889–1899:...
was processed almost immediately after it was exposed in a camera, then scanned by a television scanner, and transmitted over the air. This system was used principally in Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
and Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
where television cameras were not sensitive enough to use reflected light, but could transmit a suitable image when a bright light was shown through motion picture film directly into the camera lens. John Logie Baird
John Logie Baird
John Logie Baird FRSE was a Scottish engineer and inventor of the world's first practical, publicly demonstrated television system, and also the world's first fully electronic colour television tube...
began developing the process in 1932, borrowing the idea from his licensees in Germany, where it was demonstrated by Fernseh
Fernseh
The Fernseh AG television company was registered in Berlin on July 3, 1929 by John Logie Baird, Robert Bosch and other partners with an initial capital of 100,000 Reichsmark....
AG in 1932 and used for broadcasting in 1934. The BBC
BBC One
BBC One is the flagship television channel of the British Broadcasting Corporation in the United Kingdom. It was launched on 2 November 1936 as the BBC Television Service, and was the world's first regular television service with a high level of image resolution...
used Baird's version of the process during the first three months of its high definition television service from November 1936 through January 1937, and German television
Fernsehsender Paul Nipkow
The Fernsehsender "Paul Nipkow" Berlin was a television station in Germany. It was on the air from March 22, 1935 until it was shut down in 1944. Its headquarters were in Berlin, Germany. It was named after Paul Nipkow, the inventor of the Nipkow disk...
used it during broadcasts of the 1936 Summer Olympics
1936 Summer Olympics
The 1936 Summer Olympics, officially known as the Games of the XI Olympiad, was an international multi-sport event which was held in 1936 in Berlin, Germany. Berlin won the bid to host the Games over Barcelona, Spain on April 26, 1931, at the 29th IOC Session in Barcelona...
. In both cases, intermediate film cameras alternated with newly introduced direct television cameras.
The exposed film, either 35mm or 17.5mm (35mm split in half, to save expense), travelled in a continuous band from the camera, usually atop a remote broadcast vehicle, into a machine that developed and fixed the image. The film was then run through a flying spot scanner (so called because it moved a focused beam of light back and forth across the image), and electronically converted from a negative to a positive image. Depending on the equipment, the time from camera to scanner could be a minute or less. An optical soundtrack
Sound-on-film
Sound-on-film refers to a class of sound film processes where the sound accompanying picture is physically recorded onto photographic film, usually, but not always, the same strip of film carrying the picture. Sound-on-film processes can either record an analog sound track or digital sound track,...
was recorded onto the film, between the perforations and the edge of the film, at the same time the image was taken to keep the sound and image in synchronization.
The Intermediate film system, with its expensive film usage and relatively immobile cameras, did have the advantage that it left a filmed record of the programme which could be rerun at a different time, with a better image quality than the later kinescope
Kinescope
Kinescope , shortened to kine , also known as telerecording in Britain, is a recording of a television program made by filming the picture from a video monitor...
films, which were shot from a video monitor.
Television tubes developed by Farnsworth and Zworykin
Vladimir Zworykin
Vladimir Kozmich Zworykin was a Russian-American inventor, engineer, and pioneer of television technology. Zworykin invented a television transmitting and receiving system employing cathode ray tubes...
in the United States, and by E.M.I. in England, with much higher sensitivity to light, made the intermediate film system obsolete by 1937.
External links
- Diagram of an intermediate film remote broadcast vehicle.
- Television Apparatus, U.S. Patent application by Fernseh AG, 1932 (in Germany, 1931).
- Television Transmission Method, U.S. Patent application by Fernseh AG, 1933 (in Germany, 1932).