The Cine Technician (1953-1956)

March-April, 1953 THE CINE-TECHNICIAN 29 Natural Vision* by •Joseph Biroc9 A.S.C. TVTATURAL Vision is said to be the first 3-D -L^ system yet developed which is based on the fundamentals of natural vision, hence its name. The 3-D camera is actually two cameras in a single unit photographing separate film strips. These in turn are projected simultaneously with two projectors interlocked to run in unison. While other 3-D systems have employed dual cameras, none have pursued the theory that the 3-D cameras should see and record the scene exactly as the human eyes see it. In other words, twin cameras placed side by side and focusing directly on the scene overlook the important factor of parallax. Natural Vision's system has variable parallax as the crux of its system. The result is 3-dimensional pictures on the screen that induce no eye strain. Polaroid spectacles are worn by the audience in viewing the pictures the same as for other 3-D systems. The Natural Vision camera is an interesting piece of equipment. Available photographs show the camera in its blimp, and the unique technical details are therefore not visible. Inside the blimp are two standard Mitchell 35mm. cameras mounted on a base plate with the lens turrets facing each other. In between are two front-surface mirrors having micrometer adjustments, which reflect the scene into the camera lenses. Controls at either side of the camera base lead to the swivel-mounts holding the mirrors, and enable making the fine micrometer adjustments for the highly important parallax correction prior to shooting each scene. Thus the two cameras record the scene in left and right images, properly related with respect for parallax. In addition to moving the mirrors, there is provision for changing the viewing angle of one of the cameras. Mounted on a rotating base, this camera may be pointed at a slight angle in conjunction with the mirror adjustments to achieve the correct parallax. The usual complement of 4 lenses is missing from the camera's turrets. Only one lens is mounted on each camera, and this is changed as the need demands. The various pairs (paired for equivalent focal length) of lenses used are carefully matched and tested. Despite the apparent bulk of the camera and the need for critical adjustment of the optical equipment prior to recording each take, it is possible to attain remarkable speed in making new set-ups. This is due mainly to the facilities provided by the two cameras and viewfinder which permit the cameraman, operator and the director to scan a scene during a single rehearsal, all at the same time. This eliminates the need for separate " runthroughs " for each man, as when shooting with a two-dimensional motion picture camera. Selecting camera set-ups calls for the careful placing of people and dressing of sets, together with the careful selection of lenses of correct focal length to avoid false perspective and distortion. The operating crew working with Natural Vision cameras must be exacting in their work — much more precise than in 2-dimension cinematography. The mirrors, which are the critical centre of the system, must be carefully positioned and checked, both before and after making each shot. Thus if a mirror is found out of adjustment after the shot — a rare thing — it can be corrected and the scene reshot immediately. As a means of developing the utmost interest in Natural Vision 3-dimensional films, and particularly in Arch Oboler's initial production, " Bwana Devil," the film will be road-shown throughout the country for an undetermined period. Thereafter, the picture can be shown in 2-dimension, simply by screening one of the dual prints used in 3-D exhibition. Thus, any Natural Vision production has the added factor of being available for exhibition as either a 2-dimension or 3-dimension production. Natural Vision's 3-dimension system does not entail costly changes in theatre projection equipment. All that is necessary is a simple interlocking drive joining the movement of both projectors so that the machines operate in synchronism. Already, sensing the dawn of the era of practical 3-D motion pictures, several manufacturers of theatre projection equipment have developed linking apparatus for their machines. (Editor's note. — In addition to the interlocking drive mentioned by the author, new projector lenses and larger magazines are required. The larger reels run 40 minutes at a showing. Then a short intermission is necessary until they can be changed.) CinemaScope THE Twentieth Century-Fox Film Corporation is converting its " entire production output forthwith to a new photographic and sound system to be known as CinemaScope." Eleven major productions, representing an estimated investment of $25,000,000 will be made in the new wide-angle color photographic process. The first picture to utilise CinemaScope will be " The Robe," carrying a budget of $4,200,000. CinemaScope is a French development by Henri Chretien, honourable professor at the Sorbonne and the Paris Optical Institute. It was originally known under the name of Anamorphoscope and rights to it were acquired about three months ago in France by Mr. Skouras. The process entails a two-fold operation in photography and projection. Images are photographed by a standard camera using the customary 35mm. film. A special wideangle lens, which can be attached to the ordinary professional movie camera, takes a distorted image and compresses it onto the film. Standard projectors are similarly equipped with a special compensating lens that corrects the photographic distortion and gives the images additional size and depth when projected on a concave screen two and a half times larger that the size of the ordinary flat surface screen now in general use. In the case of theatres not equipped with the latest in sound devices, rewiring and the installation of additional speaker horns will be necessary to achieve the stereophonic sound effects, a component part of the process. In CinemaScope the sound is amplified through three horns instead of one. from the " New York Times "