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Kinescope
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Kinescope originally referred to the cathode ray tube used in television receivers, as named by inventor Vladimir Zworykin in 1929. Today it usually means a kinescope film or kinescope recording – kine for short. The process is known as telerecording in the UK. This is a recording of a television program made by filming the picture from a video monitor. Typically, the term can refer to the process itself, the equipment used for the procedure: a 16mm or 35mm movie camera mounted in front of a video monitor, and synchronized to the monitor’s scanning rate, or a film made using the process.
lass="link1" onMouseover='showByLink("m745041",this)' onMouseout='hide("m745041")'href="http://www.absoluteastronomy.com/topics/NTSC">NTSC television images are scanned at 60 Hz, or with two fields creating one frame, 30 frames per second (fps), respectively.
A kinescope must be able to:
- Convert the 30 fps image to 24 fps, the standard sound speed of film cameras,
- Do so in a way so that the image is clear enough to then re-broadcast by means of a film chain back to 30 fps.
In kinescoping an NTSC signal, 525 lines are broadcast in one frame.
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Encyclopedia
Kinescope originally referred to the cathode ray tube used in television receivers, as named by inventor Vladimir Zworykin in 1929. Today it usually means a kinescope film or kinescope recording – kine for short. The process is known as telerecording in the UK. This is a recording of a television program made by filming the picture from a video monitor. Typically, the term can refer to the process itself, the equipment used for the procedure: a 16mm or 35mm movie camera mounted in front of a video monitor, and synchronized to the monitor’s scanning rate, or a film made using the process.
How a kinescope works
NTSC television images are scanned at 60 Hz, or with two fields creating one frame, 30 frames per second (fps), respectively.
A kinescope must be able to:
- Convert the 30 fps image to 24 fps, the standard sound speed of film cameras,
- Do so in a way so that the image is clear enough to then re-broadcast by means of a film chain back to 30 fps.
In kinescoping an NTSC signal, 525 lines are broadcast in one frame. A 35mm or 16mm camera exposes one frame of film for every one frame of television (525 lines), and moving a new frame of film into place during the time equivalent of one field of television (131.25 lines).
Therefore, in order to maintain successful kinescope photography, a camera must expose one frame of film for exactly 1/30 of a second, the time of which one frame of NTSC video is transmitted, and move to another frame of film within the small interval of 1/120 of a second. In some instances, this was accomplished through means of an electronic shutter which cuts off the TV image at the end of every 525 lines.
Most kinescope situations, however, utilized a mechanical shutter, revolving at 24 revolutions per second. This shutter had a closed angle of 72° and an open angle of 288°, yielding the necessary closed time of 1/120 of a second and 1/30 of a second. Using this shutter, in 1 second of video (60 fields equaling 30 frames), 48 television fields (totaling to 24 frames of video) would be captured on 24 frames of film, and 12 additional fields would be omitted as the shutter closed and the film advanced.
Shutter bar and banding problems
Due to the 72°/288° shutter, and the systematic loss of 12 fields per second was not without its side effects. In going from 30 fps to 24 fps, the camera photographed part of some fields. The juncture on the film frame where these part-fields met was called a "splice."
If the timing was accurate, the splice was invisible. However, if the camera and television were out of phase, phenomenon known as "shutter bar" or "banding" took place. If the shutter was slow in closing, over exposure resulted where the part-fields joined and the "shutter bar" took the form of a white line. If the shutter closed too soon, underexposure took place and the line was black. The term "banding" referred to the phenomenon occurring on the screen as two bars.
This obstacle could be overcome by brushing a thin coat of lacquer on the edge of the shutter according to the phasing between the camera shutter and the TV impulses.
Lenses for kinescoping
Lenses necessary did not need a great depth of field, but of high speed and capable of producing a very sharp image with high resolution of a flat surface. In order to keep from light fall-off on the perimeter of the lens, a coated lens was preferable. 40 mm or 50 mm lenses were usually used with 16mm in calibrated mounts. Focus was checked by examining a print yielded under a microscope.
Magazines and film length
In order to record half-hour programs without interruption, magazines were designed which accommodated a load of 1,200 feet for 16 mm film. Stations recording on 35 mm utilized 6,000 foot magazines for one hour of continuous recording.
Sound recording
The camera could be equipped with sound recording to place the soundtrack and picture on the same film for single system sound recording. More commonly, the alternative system of a double system, whereby the soundtrack was recorded on an optical recorder or magnetic dubber in sync with the camera, yielded a better quality sound track and greater facilitated editing.
The kinescope image
Kinescope tubes intended for photographic use were coated with phosphors rich in blue and ultra-violet radiations. This permitted the use of positive type emulsions for photographing in spite of their slow film speeds. The brightness range of kinescope tubes were about 1 to 30.
Kinescope images were capable of great flexibility. The operator could make the image brighter or darker, adjust contrast, width and height, turn left, right or upside down, and positive or negative.
Since kinescopes were able to produce a negative picture, direct positive recordings could be made by simply photographing a negative image on the kinescope tube. When making a negative film, in order for final prints to be in the correct emulsion position, the direction of the is image was reversed on the television. This applied only when double system sound was used.
Film stock used
For kinescopes, 16 mm film was the common choice by most studios because of the lower cost of stock and film processing, but in the larger network markets, it was not uncommon to see 35 mm kinescopes, particularly for national rebroadcast. By law, all film supplied to TV stations, both 16 mm and 35 mm had to be on a non-flammable, safety film base.
For video recording, fine grain positive stock was the most common used because of its low cost and high resolution yield. Of the fine grain stocks, the following were recommended by film manufacturers:
Ansco - Fine Grain Positive for Television Purposes, for making direct positive recordings with 16mm kinescope cameras.
DuPont - Fine Grain Master Positive Film Type 628A (16 mm) and 628B (35 mm). Difference in contrast can be controlled in development.
Eastman Kodak - Eastman Fine Grain Sound Recording Film, Type 5373 (low-contrast) for negative stock where other prints would be made. Fine Grain Release Positive Film, Type 7302 (high-contrast) for direct positive recordings and single system sound recordings using variable area sound.
Other common issues with Kinescopes
Because each field is sequential in time to the next, a kinescope film frame that captured two interlaced fields at once often showed a ghostly fringe around the edges of moving objects, an artifact not as visible when watching television directly at 50 or 60 fields per second.
Some kinescopes filmed the television pictures at the same frame rate of 30 full frames per second, resulting in more faithful picture quality than those that recorded at 24 frames per second. The standard was later changed for color TV to 59.94 fields/sec. or 29.97 frame/s. when color TV was invented.
In recent years, the BBC has introduced a video process called VidFIRE, which can restore kinescope recordings to their original frame rate by interpolating video fields between the film frames.
Early Experiments in Kinescoping
According to a 1949 film produced by RCA, silent films had been made of early experimental telecasts during the 1930s. The films were shot off television monitors at a speed of eight frames per second, resulting in somewhat jerky reproductions of the images. By the mid 1940s, RCA and NBC were refining the filming process and including sound; the images were less jerky but still somewhat fuzzy.
During World War II, television cameras were attached to guided missiles to aid in their remote steering. 35 mm films were made of the television images they transmitted for further evaluation of the target and the missile's performance.
Introduction of the Eastman Television Recording Camera
In September 1947, Kodak introduced the Eastman Television Recording Camera, in cooperation with DuMont Laboratories, Inc. and NBC, for recording images from a television screen under the trademark "Kinephoto". Prior to the introduction of videotape in 1956, kinescopes were the only way to record television broadcasts, or to distribute network programs that were broadcast live from New York or other originating cities, to stations not connected to the network, or to stations that wished to show a program at a different time than the network broadcast. Although the quality was less than desirable, television programs of all types from prestigious dramas to regular news shows were handled in this manner.
NBC, CBS, and DuMont set up their main kinescope recording facilities in New York City, while ABC chose Chicago. By 1951, NBC and CBS were each shipping out some 1,000 16mm kinescope prints each week to their affiliates across the United States, and by 1955 that number had increased to 2,500 per week for CBS. The television industry’s film consumption eventually surpassed that of all of the Hollywood studios combined.
"Hot kinescope"
After the network of coaxial cable and microwave relays carrying programs to the west coast was completed in September 1951, CBS and NBC in 1952 instituted a "hot kinescope" process in which shows being performed in New York were transmitted west, filmed on two kinescope machines in 35 mm negative and 16 mm reversal film (the latter for backup protection) in Los Angeles, rushed to film processing, and then transmitted from Los Angeles three hours later for broadcast in the Pacific Time Zone.
In September 1956, NBC began making color "hot kines" of some of its color programs using a lenticular film process which, unlike color negative film, could be processed rapidly using standard black and white methods.
Double system method of editing
Even after the introduction of Quadruplex videotape machines in 1956 removed the need for "hot kines", the television networks continued to use kinescopes in the "double system" method of videotape editing. It was impossible to slow or freeze frame a videotape at that time, so the unedited tape would be copied to a kinescope, and edited conventionally. The edited kinescope print was then used to conform the videotape master. More than 300 videotaped network series and specials used this method over a 12-year period, including the fast-paced Rowan & Martin's Laugh-In.
Alternatives to Kinescoping
With the variable quality of Kinescopes, networks looked towards alternative methods to replace them with a higher degree of quality.
Change to 35 mm film broadcasts
Filmed programs were also used in television’s early years, although they were generally considered inferior to the big-production "live" programs because of their lower budgets and loss of immediacy. This, however, was about to change.
In 1951, the stars and producers of the Hollywood-based I Love Lucy, Desi Arnaz and Lucille Ball, decided to shoot their show directly onto 35 mm film using the three-camera system, instead of broadcasting it live. Normally, a live program originating from Los Angeles (for example, The Frank Sinatra Show) would be performed live in the late afternoon for the Eastern Time Zone, and seen on a kinescope three hours later in the Pacific Time Zone. But as an article in American Cinematographer explained,
- In the beginning there was a very definite reason for the decision of Desilu Productions to put I Love Lucy on film instead of doing it live and having kinescope recordings carry it to affiliate outlets of the network. The company was not satisfied with the quality of kinescopes. It saw that film, produced especially for television, was the only means of insuring top quality pictures on the home receiver as well as insuring a flawless show.
The I Love Lucy decision introduced reruns to most of the American television audience, and set a pattern for the syndication of TV shows after their network runs (and later, for first-run airings via syndication) that continues to this day.
Electronicam
The program director of the short-lived DuMont Television Network, James Caddigan, devised an alternative—the Electronicam. In this system, all the studio TV cameras had built-in 35 mm film cameras which shared the same optical path. An Electronicam technician threw switches to mark the film footage electronically, identifying the camera "takes" called by the director. The corresponding film segments from the various cameras then were combined by a film editor to duplicate the live program. The 39 syndicated episodes of The Honeymooners were filmed using Electronicam, but with the introduction of a practical videotape recorder only one year away, the Electronicam system never saw widespread use. The DuMont network did not survive into the era of videotape, and in order to gain clearances for its programs, was heavily dependent on kinescopes, which it called teletranscriptions.
Videotape
As new technologies for storing video became available, kinescopes slowly began to fade in importance: In 1951, singer Bing Crosby’s company Bing Crosby Enterprises made the first experimental magnetic video recordings; however, the poor picture quality and very high tape speed meant it would be impractical to use. In 1956, Ampex introduced the first commercial Quadruplex videotape recorder, followed in 1958 by a color model.
The last years of the Kinescopes
The networks continued to make kinescopes of their daytime dramas (many of which still aired live into the late 1960s) available as late as 1969 for their smaller network affiliates that did not yet have videotape capability but wished to time-shift the network programming. Some of these programs aired up to two weeks after their original dates, particularly in Alaska and Hawaii. Many episodes of programs from the 1960s survive only through kinescoped copies. The last 16 mm kinescopes of television programs ended in the late 1970s, as video tape recorders became more affordable.
In Australia, kinescopes were still being made of some evening news programs as late as 1977, if they were recorded at all.
In later years, film and television producers were often reluctant to include kinescope footage in anthologies, because of the "inferior" quality. While it is true that kinescopes did look inferior to live transmissions in the 1950s, it was due to the industry's technical limitations at that time. Even the best live transmission could look contrasty or hazy by the time it reached the home viewer. Advances in broadcast technology soon allowed for a wider gray scale in black-and-white, and a fuller spectrum of colors, making kinescopes a perfectly viable commodity. This was demonstrated in the feature film Ten from Your Show of Shows, a compilation of Sid Caesar kinescopes released to theaters. Reviewers were astonished at how good the kinescoped image looked on a large screen. Kinescopes have since lost their stigma of inferiority, and are commonly consulted today for archival purposes.
Status of kinescopes today
Kinescopes were intended to be used for immediate rebroadcast, or for an occasional repeat of a prerecorded program; thus, only a small fraction of kinescope recordings remain today. Many television shows are represented by only a handful of episodes, such as with the early television work of comedian Ernie Kovacs, and the original version of Jeopardy! hosted by Art Fleming.
Certain performers or production companies would require that a kinescope be made of every television program. Such is the case with performers Jackie Gleason and Milton Berle, for whom nearly complete program archives exist. As Jackie Gleason’s program was broadcast live in New York, the show was kinescoped for later rebroadcast for the West Coast. After these programs were shown, the kinescopes would be returned to Gleason, who kept them in his vault, and only released them to the public shortly before his death in 1987.
Milton Berle sued NBC late in his life, believing the kinescopes of a major portion of his programs were lost. However, the programs were later found in a warehouse in Los Angeles.
Mark Goodson-Bill Todman Productions, the producers of such TV game shows as What’s My Line?, had a significant portion of their output recorded on both videotape and kinescopes. These programs are rebroadcast on the American cable TV’s Game Show Network.
All of the NBC Symphony Orchestra telecasts with Arturo Toscanini, from 1948 to 1952, were preserved on kinescopes and later released on VHS and laser disc by RCA and on DVD by Testament. The original audio from the kinescopes, however, was replaced with high fidelity sound that had been recorded simultaneously either on transcription discs or magnetic tape.
In the mid-90's, Edie Adams, wife of Ernie Kovacs, claimed that so little value was given to the kinescope recordings of the DuMont Television Network that after the network folded in 1956 its entire archive was dumped into upper New York bay. Today however, efforts are made to preserve the few surviving DuMont kinescopes, with the UCLA Film and Television Archive having collected over 300 for preservation.
External links
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- , U.S. patent application, 1945.
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