British Kinematography (1950)

December, 1950 cricks : engineering aspects of film production 197 II— CAMERA SUPPORTS. In the early days of the sound film, the camera was rendered immobile by the requirements of the microphone, and was often placed inside a sound-proofed booth. To-day the camera is required to be freely mobile in every direction. Flexibility of camera movement is made more difficult by the increasing weight of cameras — colour cameras in particular. The Technicolor camera, for instance, in its sound-proof blimp, weighs no less than 640 lb. The most popular form of camera support is known for some inscrutable reason as the " dolly." A more elaborate device is the camera crane ; cranes range in size from a type small enough to pass through a standard doorway, up to massive structures, capable of lifting the camera and its crew 20 feet or 30 feet into the air. Where the camera is required to track during shooting, temporary rails of wood, or preferably duralumin, are laid. In a recent French film, the whole of the first reel was occupied by a single tracking shot, for which 200 feet of rails were laid. Recording Camera Movement. To appreciate the value of modern developments in camera control, it is necessary to picture the sequence of operations in shooting a scene. The camera positions and movements will be laid down approximately in the shooting script ; during rehearsal they will gradually become finalised, and must then be repeated with as close accuracy as possible. A system has therefore been devised whereby a record of the movements of the camera in three directions, together with a record of the focal adjustments of the lens, is recorded during rehearsal, in the form of tracks of variable frequency upon a gramophone disc ; this is reproduced during shooting, and controls every movement of the camera, ensuring accurate repetition of camera movement.4 While the device described is of American origin, a similar system is in experimental use in a British studio. Travelling Matte Process. An objection to the use of such systems is that actors cannot be controlled by similar automatic means, and frequently ruin a take by stepping outside their limits. There is, however, one type of shot to which this does not apply, and which indeed is rendered possible only by some automatic control of this type. An example of such a shot might be a model in which live action is required. In one method of producing such an effect, the model is filmed, leaving a blank space where the action is to appear. The small full-scale set where the action is to take place is built in the studio. The camera is threaded with two films : a print from the first film, in front of negative stock. The image on the front or matte film prints through, and the final negative consists of an image of the model, and in the blank space the photograph of the action. This is known as the travelling matte process. Effects of this nature have in the past been possible only with a stationary camera, because obviously any camera movement in the filming of the model shot must be exactly duplicated in the filming of the live action. But with the aid of an automatic method of ensuring exact repetition of camera movement, it is possible for movement to be exactly repeated, and the camera thus regains its mobility. Ill— CAMERAS AND PROJECTORS. Every camera and projector — and indeed most other film equipment — ■ embodies the same essentials as were devised by William Friese-Greene5 sixty years ago : a take-off reel, a continuous feed sprocket feeding the film through