Magazine article American Cinematographer

Automated Focusing Systems

Magazine article American Cinematographer

Automated Focusing Systems

Article excerpt

The ability to keep a moving object in focus whether it is Spend A Buck crossing the finish line, a hit man in a crowded airport, or John Wayne and the cavalry cresting the ridge has always been a major limitation for cameramen working in video or film. Three new automatic focusing systems, available in various stages of research and devel npment. are opening up new areas of artistry and technology for today's earn eraman by refining or eliminating follow focusing problems.

Richard Vye of Computer Dig ital Focusing, Gary Gem and Dr. Robert Bogle of BG Associates, and John Sen? of Seit? lechnical Products have ap proached the problem from differer an gles and each system varies in its suitability to practical problems

Richard Vye's system was originally designed for video with an eye to improved sports coverage. It uses a clear, graphics digitizer pad and a light pen and depends on the ability of the operator to follow the action. The pad is set up between the cameraman and the action. Using the stylus, the operator follows the ob|ect of the action the lead car in the Indianapolis 500, for example.

The tablet and pen relay streams of 200 x y coordinate pairs per second to the 8088 CPU In turn this information is converted into exact dis tances for as many as 10 linked video cameras All the cameras will be in critical focus wherever the light pen is. A major advantage to the system is its ability to stabilize the long telephoto shot. The telephoto focus "jump" is eliminated.

Although the system was originally developed for video, Vye's re search and development is moving the company steadily towards film produc tion. A lens is a lens and adjusting the hardware for 35mm cameras is a rela lively simple task. With a program developed with his son, Vye can compute lens parameters on any lens within sec onds, making the system very flexible He is alo beginning the design phase for a system that would allow pan and tilt control from the graphics pad.

For more information contact: Richard Vye, Computer Digital Focusing, 2603 Centinela Ave., Santa Monica, CA, 90405, (213| 4504243

GB Associates have developed a system called Radarfocus which allows fully automatic focusing from infinity to six feet by using microwave and digital electronics technology The heart of the system is a miniature radio transponder which holds tight focus on a predesignated subject.

Brianne Murphy, ASC, and Ted Voightlander, ASC, are giving this system its first professional workout in this season's episodes of "Highway to Heaven," a Michael Landon Production. Murphy, who was intrigued by the artistic aspects of Radarfocus, also recog nizes the safety feature. "It eliminates dangerous situations for operators and assistants," she said. She .envisions many applications, such as following animals which are unlikely to consistently hit their mark or, on a more spectacular level, attaching a transponder to a surfer and following the action with a 250rnm lens.

The system has basically two parts a cigarette package sized transponder which is planted on the person or object to be kept in focus and a camera mounted tracking head. Unique digital processing circuits make Radarfocus compatible with a wide range of lenses. Quick change modules are available for lens interchange and the system is adaptable to film and video cameras.

Gero indicated that as part of his research and development, he is busy designing a complete system that would control all camera movements For more information contact: Linda Bogle, Marketing Representative, 6714 Wardlow Rd., Long Beach, CA 90808, (213) 421 1091.

Along the same lines, Seitz Technical Products, Inc. has designed the 8700A Follow Focus Radio System which actually provides three channels of servo control - focus, iris and zoom. With this system the assistant is not tied to the camera at all. He can start and stop it, follow focus and with the addition of two more servo channels, pan and tilt the camera from a remote location. …

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