Television Broadcast

On July 1, NPR’s “All Things Considered” featured an interview with David Maraniss, author of Rome 1960: The Olympics That Changed the World. The writer described Jim McKay warming footage just flown to New York so it could be aired. It was said to be the first televised Olympics. But it wasn’t.

“On the Reich Sports Field, television transmissions can be carried out from all important contest grounds over the television transmitter Witzleben. Television stands for picking up the events are provided in the Olympic Stadium at the end of the 100 m [track], at the Swimming Stadium, at the Marathon Gate (May Field), on the Dietrich Eckart Open-Air Theatre and at some other places. Two special television cables connect the Reich Sports Field with the television transmitter at the Berlin radio tower.”

A Fernsehkanone used at the 1936 Olympics.

The previous paragraph is from a multilanguage booklet distributed at what were really the first Olympic Games to be televised—1936 in Berlin. In addition to describing some of the Olympics’ television facilities, the brochure noted that visitors could also book videophone calls at multiple “public television offices.”

But the technology used for the games was more fascinating.

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Most understandable to us would be the “television cannons.” These devices, each about the size of a pregnant walrus, were electronic television cameras with viewfinders, operated by technicians in fashionable attire created just for the occasion.

Telefunken offered iconoscope-based technology with telescopic lenses that gave the cameras their names. Spectators might have wondered whether they were looking at optical or ballistic devices, each cylinder about a foot in diameter.

The German Post Office provided a smaller iconoscope-based camera in the swimming stadium, and Fernseh AG (one of the ancestors of today’s Grass Valley cameras) provided one that was smaller still, based on Farnsworth’s image dissector technology. The latter was said by Frithjof Rudert, in a historical article on Fernseh, to have “delivered very sharp signals, free of interference components, but only in bright weather.”

What was done when it got cloudy?

“The outside broadcast van using the intermediate-film process had the advantage of mobility and could take topical pictures in any weather.”

That truck was about the size of a moving van and it had a platform on top with railings around it, allowing those fashionably attired technicians to operate a film camera mounted on a pedestal. The camera used 35 mm film, but it was definitely not an ordinary film camera.

For one thing, instead of shooting common 18-by-24 mm frames, it shot frames just 9-by-12 mm, allowing much more time to be captured on a single reel. For another, the film-supply reel was enormous, rivaling the platters used in today’s cinemas. And, most significant, there was no take-up reel.

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That is to say there was no take-up reel mounted on the camera. Instead, it fed its exposed film through the hollow pedestal into the interior of the van, where it entered a mobile film-processing laboratory.

The chemical baths used extremely high concentrations of developer and fixer and were maintained at optimum temperatures—for the film (the technicians had to deal with lethal fumes). The developed film then passed through a hot-air dryer, completing its chemical processing.

A clipping from Popular Mechanics magazine, circa November, 1936.

That’s when the electronic processing began. The negative was fed into a film scanner. It was, in effect, a carbon-arc-based theatrical projector aimed into a spinning-discbased video camera. Less than 85 seconds elapsed from the time the film was shot until a video signal left the truck.

The film truck, like the electronic cameras, generated a signal of 180 lines at 25 frames per second (called “high definition” at the time, because previous broadcasts had just 30 lines). Receivers using picture tubes recognizable today displayed the broadcasts to small groups. But there were also larger groups—150,000 in 28 “public television rooms.”

At the 1933 Radio Exhibition, Fernseh showed one way to deal with large-screen projection, reversing the intermediate-film process. A continuous 70-meter loop of film was coated with emulsion, exposed by a mechanical scanner, processed, and projected to an audience. Then the emulsion was washed off, the film was dried, and the process repeated.

Believe it or not, it actually worked! But by 1936, Fernseh had developed video projectors based on high-brightness picture tubes, filling 4-foot-wide screens.

Will the Beijing Games top that?

Mark Schubin is an engineering consultant with a diverse range of clients, from the Metropolitan Opera to Sesame Workshop. (Originally published in Television Broadcast, July 2008. All Rights Reserved)

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