British Kinematography (1953)

38 BRITISH KINEMATOGRAPHY Vol. 22, No. 2 cinematography, and further describes the dual Newman-Sinclair outfit used for many of the Festival films.14 The method by which two Technicolor cameras were paired up for stereo cinematography has also been described.15 All this British pioneer work has clearly had a considerable influence on Hollywood, which appears to be progressing along similar lines in the development of its stereo systems. Hollywood has launched into 3-D (American for three dimensional) cinematography with the Natural Vision Corporation's system, which takes two films simultaneously in two standard Mitchell cameras placed with their lenses facing each other. A mirror before each lens reflects the scene into the lens, and enables the usual stereo adjustments to be made. The double camera assembly is mounted in a special blimp and has been used on an Ansco Color production, " Bwana Devil. "" A Dutch stereo system takes both the L and R eye images on one film, using a camera with a two frame pull-down, two matched lenses one below the other, and mirrors on adjustable mounts to provide the necessary stereo adjustments.17 High Speed Equipment Military research accounts for much of the past year's progress in camera equipment, In evaluating the performance of rocket missiles various types of camera are employed. The missiles are often filmed from a distance of several miles, a typical installation being on a tracking telescope with an equivalent focal length of 20ft. Records of azimuth, elevation and time, are also photographed on each 35mm. frame by a suitable addition to the standard type of camera employed. One camera is fitted to a tracking telescope with an equivalent focal length of from 40 to 80 ft., the installation being located some 40 miles from the launching site.18 For recording the launching and flight of missiles the U.S. Navy are using batteries of Mitchell High Speed cameras adapted to take medium long focus lenses.19 In Britain, the Ministry of Supply has exhibited at the Society of British Aircraft Constructors' Exhibition at Farnborough a short film taken with long focus lenses on Vinten H.S. 300 and Debrie High Speed cameras, showing various aspects of rocket research. While the high speed cameras so far mentioned have employed intermittent movements, progress has also continued on high speed cameras in which the film moves continuously. Acmade Ltd. have now built several production models of their camera, the prototype of which made its appearance just over a year ago. This camera has a maximum speed of 2,000 frames per second, or 4,000 with half frame-height images. Film from a 200-ft. magazine moves continuously on a large sprocket geared to which is a rotating glass block located between the Fig. 2. The Vinten H.S. 300 camera fitted with 36-inch telephoto lens. lens and the film to provide optical compensation for film movement. An ingenious photo-electric device on the camera triggers the recently described power stroboscope, which flashes once per frame. The flash duration is about 5 micro-seconds, and the energy of the flash is 4 Joules.20 A French ultra-high speed camera gives a speed up to 100,000 frames per second, upon a 75-inch length of film threaded against the inner surface of a drum, around the outside of which is fixed a ring of lenses. This rotating lens drum thus carries the film around with it and provides optical compensation for film movement.21 An even more specialized ultra-high speed 35mm. camera is the simple rotating drum model made by the Illinois Institute of Tech