Radio age research, manufacturing, communications, broadcasting, television (1941)

VIDEO INSET OUTPUT TO TRANSMITTER Sketch shows how NBC's new color video inset employs two cameras to control foreground of a TV picture independently of the background to achieve novel effects. 4J_ VIDEO SEPARATOR RELAY BACKGROUND SCENE FOREGROUND CAMERA A MONITOR (COMPOSITE) BLACK BACKDROP New Visual Effects for Color TV A SERIES of visual effects new to live television pro- gramming added spice to a number of NBC major color programs during November and December, marking the debut of a versatile new tool in telecasting. The results appeared dramatically for the first time in "Alice in Wonderland," when Alice seemed to shrink in size before the camera while surrounding objects re- mained unchanged. In the Sadler's Wells Ballet produc- tion of "Sleeping Beauty," Margot Fonteyn, as the princess, appeared in one scene to float before the camera as a vision brought to Prince Charming and his retinue in the magic forest. Behind these and other novel effects in other major programs, lay an ingenious NBC system known as the "color video inset," employing two cameras in a way which permits the foreground of a picture to be con- trolled independently of the background. The system was developed by the NBC Engineering Department, and was one of the last projects carried out under super- vision of Robert E. Shelby, Vice-President and Chief Engineer of NBC, before his death on December S. In announcing the successful use of the new system, Mr. Shelby had declared: "This is one of the most im- portant developments to come out of the NBC Engi- neering Department. With the new system, producers can use camera techniques heretofore impossible in live color television. They can, for example, create giant 'spectacles' in relatively small studios, and they can bring a live outdoor scene into the studio to be used as a background." How it Works The "color video inset" works this way: Two cameras are used simultaneously, one scanning a background scene, and the other scanning the inset object, which is placed against a black backdrop. An electronic mixing device automatically records a sil- houette of the inset object (Alice, for example, in the shrinking scene), then "cuts" a correspondingly shaped hole in the background and makes the insert. The process requires precise control in production work as well as in electronic timing, which must be accurate to one ten-millionth of a second. The effect of the inset, unlike that of a superim- posed television image, is to present a solid picture without overlapping or transparency. In this respect, the new system is similar to the matting process in film, which requires complex lighting and processing work. Thus the inset permits the instantaneous use of live camera effects which could be achieved formerly only with the use of processed film. NBC engineers have pointed out that the color video inset broadens the whole scope of color television pro- duction. With its use, an actor may be placed against the background of a mountainside, a city street, or a seashore, brought into the studio "live" from any location that can be reached with a television camera. Or, doing it the other way around, actors may be placed in spectacular settings which may be set up in miniature in the same studio, or even in another studio —the inset system reducing the apparent size of the actor to fit the background. The color video inset is an extension and refinement of the black-and-white video inset. Both techniques were pioneered by the Development Group of the NBC Engineering Department, which interprets and adapts the laboratory research of RCA to the broadcasting uses of NBC. RADIO AGE 31