A 35mm lenticular film used to record color television onto B/W reversal film during the mid-1950s.
Film Explorer
Eastman Embossed Kinescope Recording Film was a 35mm lenticular camera reversal stock used for capturing color television programs. These copies were B/W – the color was revealed again during telecine.
Design by Christian Zavanaiu.
Identification
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The physical film appears B/W, but a full color image was revealed during the telecine process.
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B/W reversal, embossed with lenticules on the base side of the film.
Standard US Eastman Kodak edge markings.
History
In 1954, the first color television programs were broadcast in the United States. North America is divided into four time zones, with a three-hour time difference between the East and West coasts. The most popular primetime programs aired in the early evening, when advertisers wanted to reach their largest audience – therefore, broadcasts for the West Coast were delayed by recording shows, and subsequently playing them back a few hours later. As magnetic-tape image recording was still in its infancy, a transitional technological solution was required to provide a solution.
The kinescope device was adopted. It involved capturing images produced by a cathode-ray tube television display onto film. This recording technique was straightforward for B/W broadcasts. However, for color programs, it was necessary to record three color records from separate red, green and blue (RGB) phosphor tubes.
Eastman Kodak's research laboratory came up with the idea of using an embossed film to capture color on a B/W reversal emulsion, which was first marketed in 1956 as Eastman Embossed Kinescope Recording Film (Hughes, 1956: p. 359). There was nothing new about this technology. The lenticular process, better known as the Keller-Dorian process in France, had already had its moment in the 1920s. In 1928, Eastman Kodak had acquired the patents from Keller-Dorian and exploited this process for 16mm, naming it Kodacolor. Eastman Kodak eventually mastered the technology, in particular the film embossing process.
Lenticular film featured tiny lenses, heat-engraved onto the film support. For recording television broadcasts, an RGB banded filter on the camera lens enabled a three-color selection to be made behind the embossings, onto a single strip of 35mm B/W reversal film. This could be processed very quickly at the transmitting station for rebroadcast, via telecine, in less than three hours.
The additive, lenticular process was preferred to chromogenic subtractive processes such as Anscoschrome, which required more complex, consequently slower, laboratory processing. Conversely, B/W reversal processing could be carried out very quickly at the network's transmitting stations.
The use of this “old fashioned” lenticular technology for Kinescope recordings did not last long. It was notably used for some productions at NBC, but was phased out within two years – by 1958 – as two-inch color videotape technology advanced and became widely adopted.
Selected Filmography
An hour-long television variety show released under the umbrella series title “Saturday Color Carnival”. The June 8, 1957, episode survives in the Jerry Lewis collection at the Library of Congress, Culpeper, VA, United States. The show guest features Eydie Gorme, Dick Humphrey, Dan Rowan, Dick Martin and Lori Spencer.
An hour-long television variety show released under the umbrella series title “Saturday Color Carnival”. The June 8, 1957, episode survives in the Jerry Lewis collection at the Library of Congress, Culpeper, VA, United States. The show guest features Eydie Gorme, Dick Humphrey, Dan Rowan, Dick Martin and Lori Spencer.
A weekly hour-long television variety show. At least some portions of episodes survive in lenticular reversal copies, including an excerpt of tap dancer John Bubbles, at the Library of Congress, Culpeper, VA, United States.
A weekly hour-long television variety show. At least some portions of episodes survive in lenticular reversal copies, including an excerpt of tap dancer John Bubbles, at the Library of Congress, Culpeper, VA, United States.
Technology
The 35mm film made by Eastman Kodak was embossed in a horizontal orientation, with an embossing pitch of 25 lenticules per mm (640 lines/in) (Tarnovski, 1958: p. 123); each lenticule measured around 40 μm (0.157 in) wide. This resolution was considered sufficient to record standard 525-line television images onto embossed reversal film. The lens used on the camera was a 75mm spherical Zeiss Tessar. Two methods of reproduction were proposed:
1. Kinescope by spectral separation
A three-color banded filter was attached to the front of the camera lens, with its bands in parallel with the film lenticules. The film was loaded with the embossed support towards the camera lens (the opposite of standard practice) – spectral separation occurred behind each lenticule, so that the separate red, green and blue color records, produced by the three-could be captured. An RGB-banded filter image reached the light-sensitive emulsion behind each embossed microlens – a three-color record on a single film was the result.
The Kinescope lens filter employed four horizontal color bands (B,R,G,B), instead of the three used in other lenticular film processes (Keller-Dorian, Siemens-Opticolor, Kodacolor). This feature reduced vignetting (a dimming of the image towards its edges). If captured light overflowed, from one lenticule to another, the blue record could be captured twice, which was not a major drawback.
Images recorded in the outer areas behind each lenticule were less defined than those recorded closer to the optical axis of each microlens: this is why the blue bands were placed on either side of the filter, as the blue record contributed the least to overall image definition.
The banded filter on the lens resulted in a loss of the light reaching the film emulsion. This loss could be compensated for, provided the signal-to-noise ratio was sufficiently high, by amplification via the video camera (vidicon) tube .
After reversal processing, the positive obtained could be run through a telecine machine, with a similar RGB filter used to reconstruct a full color image.
2. Kinescope by geometric separation
To overcome the above-noted light-loss issues, in 1958, a “geometric separation” approach was proposed (Tarnovsky, 1958: p. 128):
The RGB banded filter could be removed for color kinescope recording if the selection images coming from the three tubes were separated. The image from each tube was recorded through a clear aperture (without a color filter) corresponding in size and position.
With this geometric separation method, no three-color selection filter was used. The emulsion used was exclusively sensitive to blue radiation. It was preferable to the “spectral method”, as it offered greater light-sensitivity and accuracy in color rendition (Evans & Smith, 1956: p. 369).
References
Hughes, William L. (1956). “Recent Improvements in Black-and-White Film Recording for Color Television Use”. Journal of the SMPTE, 65:7 (July): pp. 359–64. https://archive.org/details/sim_smpte-motion-imaging-journal_1956-07_65_7/page/358/mode/2up (accessed January 30, 2025).
Evans C. H. & R. B. Smith, “Color Kinescope Recording on Embossed films”. Journal of the SMPTE, 65:7 (July): pp. 365–72. https://archive.org/details/sim_smpte-motion-imaging-journal_1956-07_65_7/page/364/mode/2up (accessed January 30, 2025).
Schneider, Arthur (1977). Jump Cut!: Memoirs of a Pioneer Television Editor. Jefferson, NC: Mc Farland & Company.
Tarnowski, A. (1958) “Colour kinescope recording on embossed film”. British Kinematography, 32:5 (May): pp. 123–36
Patents
Smith, Robert B. & Charles H. Evans. Recording of Color Television Programs. US Patent US2912488, filed July 1, 1955, and issued November 10, 1959. https://patents.google.com/patent/US2912488A/
Smith, Robert B. Process for Embossing Film. US Patent US2928135, filed January 7, 1957, and issued March 15, 1960. https://patents.google.com/patent/US2928135A/
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Author
François Ede is a cinematographer and a documentary filmmaker. He has restored several films shot with the Keller-Dorian process, including Jour de fête in 1994 and recently carried out the reconstruction and restoration of Abel Gance's La Roue (1923) for the Jérôme Seydoux-Pathé Foundation.
Special thanks to Geo. Willeman at the Library of Congress.
Ede, François (2025). “Eastman Embossed Kinescope Recording Film”. In James Layton (ed.), Film Atlas. www.filmatlas.com. Brussels: International Federation of Film Archives / Rochester, NY: George Eastman Museum.
