The film and television system with an intermediate film, Zwischenfilm ( German Zwischenfilmverfahren ) is a television system for transmitting a moving image using an intermediate film instead of a television transmitting camera [1] . Since 1934, she worked on German television because of the unsuitability of the first electronic cameras with a low-sensitivity iconoscope for field shooting. Widely used during the Berlin Olympics in 1936 [1] . Since November of the same year, it has been used in the UK for the first three months of regular broadcasting by the BBC .
Content
Principle of action
The system was mounted on the bus chassis and could move independently to the scene. For shooting images and recording sound, we used (see the figure) a movie camera 1 mounted on the roof of a bus. The optical phonogram was recorded in the camera on a film together with the image for their synchronization during the subsequent reproduction [2] . The exposed negative film was fed down the opaque chute to the developing machine 2 [1] . The design of the chute and the attachment of the apparatus made it possible to rotate the camera for horizontal panning within the limits limited by the permissible film twist. After chemical-photographic processing, the developed and fixed film was washed in tank 3 and entered the drying cabinet 4. The finished film went to the TV projector 5, where the negative image was transformed into a positive television video signal transmitted via cable 7 to the television center . The combined phonogram was read here, so that the sound lag fully corresponded to the time delay of the image. Monitor 6 allowed to control image quality. Upon arrival at the filming location, the system was connected to the water supply system 9 and the sewage system 8 for the circulation of wash water, but could also work autonomously.
The speed of motion of the film in the developing machine was selected in accordance with the shooting frequency and the projection of 25 frames per second, which coincided with the frame frequency of the standard for decomposition in 180 lines adopted in Germany with progressive scanning [1] . High-speed chemicals allowed the film to be processed so quickly that the image delay was 1-2 minutes [2] . In addition, this technology for the first time allowed to re-show the most interesting moments, which is especially important when organizing sports broadcasts. In the absence of video recording technology, an additional advantage of the system was the preservation of the captured image with the cinematic quality that is inaccessible during the recording of the television signal from the kinescope . This made it possible to carry out repeated transmissions of events and even to use shooting in newsreels . The disadvantage of such a technology of shooting was the high cost of film and the inability to quickly change the point of shooting, because the bus with the equipment was installed permanently. There could be no editing whatsoever, so all the TV reports filmed using the cinema system show the event from one point in one frame. In addition, the need for continuous operation of the camera, processor and projector mechanisms reduced the reliability of the system, which, in the event of a film break, required complex recharging and became inoperable.
There was a kind of technology that used a film ring, the emulsion of which was washed off after the TV-film projection, and instead it was watered fresh, ready for a new exposure [2] . This method allowed to reduce the cost of film, providing almost complete regeneration of silver . However, in this form, the system was even more complicated and, moreover, did not allow repetition and save the image. Twice the savings brought cutting the standard 35 mm film in half, to a width of 17.5 mm. Reducing the frame size did not affect the quality of the 180-line image. After 1937, with the advent of highly sensitive superbikonoskopov and superorticons , the cinema-based television and television systems were abandoned in favor of more mobile electronic cameras, which allowed them to shoot in a multi-camera way without a time delay.
Other uses
In some countries, including the USSR , attempts have been made to adapt this technology to display a television image on a large screen [3] . For this, the image obtained by the kinescope was filmed on film, and after a quick development it was shown by a film projector . However, the extremely low quality of the resulting image forced to abandon such an application of βzwishenfilmβ.
See also
- Phototelevision device
- Film recording video
- Eidofor
Notes
- β 1 2 3 4 Olympic television - 70 years, 2006 .
- β 1 2 3 Michael Buckland. Emanuel Goldberg, Television & Zeiss Ikon (Eng.) . School of Information Management & Systems (1995). The appeal date is November 24, 2012. Archived January 9, 2013.
- β Fast processing of photosensitive materials . School for teaching photography . The appeal date is November 24, 2012. Archived January 9, 2013.
Literature
- Vladimir Makoveev. Olympic television is 70 years old! The 1936 Berlin Olympics (Rus.) // Broadcasting: magazine. - 2006. - β 5 .
Links
- Deutschland 1936 Olympia in Berlin Fernsehwagen nach dem Zwischenfilmverfahren (German) . YouTube . The appeal date is November 24, 2012.