Proceedings of the British Kinematograph Society (1931)

photographed through an overall ‘‘ K”’ filter. This summarises the first phase, or consideration,which naturally is to secure a solid original negative of actors through a given scene without a selective exposure obstruction caused by the transparency placed in front of the raw stock. The second phase, as practised now, occurs automatically and simultaneously with the first phase. It is a printing and not a photographic operation. In other words, behind the actors, and preferably out of focus, is a flat wall or curtain illuminated with blue light, approximately complementary to the orange image of the transparency in the camera. This is large enough to act as a printing light for the entire area of the transparency frame, except those portions obstructed momentarily by the actors or foreground set. The blue light passes through the neutral portions of the transparency, but, unlike the yellow light from the actors, it is absorbed by the orange portions of the transparent background scene. And thus it creates around, and apparently behind, the actors on the same raw stock a printed contact négative exposure of the background scene. The result is a complete composite negative which is developed in the usual manner, and exhibition prints made therefrom along with the regular work in any commercial laboratory. In all cases the producer sees the finished results on the screen next morning, when he is viewing the ‘‘ dailies’ of the previous day. The composite negative of foreground and background being photographed simultaneously, there is no fringing or “ white line’ around the action, as occurs when the matte method is employed. PROCESS BACKGROUNDS. All scenes which are to be used as process backgrounds should be selected with care. Process work is effective only when well done, very important roles being played by the following elements : Quality, over-emphasis, focus perspective, angle, the height, and the steadiness. Quality.—To obtain the best backgrounds, one should try for a normal quality negative, normally developed. Under-exposed and over-developed negatives are apt to be grainy, and may show even a slight increase of graininess in process work. Negatives which have been highly over-corrected by using coloured filters may appear muddy in landscapes unless the sky areas are well broken up by cloud effects. Over-emphasis.—Halation is another fault of such negatives. Over-exposed negatives often have so much contrast that it becomes very difficult to avoid phantom effects : that is, the high lights of the transparency may be so empty as to make it difficult to obtain a value for the absorption filter for the dispositive portions which will correspond to the shadows of the positive portions in the transparency. Focus.—This is an important point when shooting backgrounds. Some argue, and quite rightly, that all close-ups and medium shots in straight photography show a background either out of focus or blurred. Others claim that such results are due simply to the inherent limitations of ordinary photography, and need not be duplicated if they can be overcome by process photography. When the eye is focussed on a near-by object, it does not see the distant scene simultaneously ; but it momentarily and rapidly focusses from one plane to another, and registers the composite sharp impression of planes at all distances from it. Experience shows that it is better to shoot a background scene focussed comparatively sharply; and then, if necessary, to soften it either by printing by optical means when making the transparency, or by controlling the illumination when making the double exposure. Therefore, all backgrounds should be focussed from 25 feet to infinity. Fifty mm. lenses are used in most cases. Perspective.—The most important accessories required when shooting backgrounds are an excellent imagination and a bevel protractor obtainable at any hardware store. The cameraman should see in his mind’s eye the foreground action that is later to be incorporated into the composite picture. Perhaps it is to be a scene showing a ten-foot length of steamer deck backed by a railing, with the rolling ocean beyond doubled in. Several passengers are to be placed in steamer chairs, and two lovers are going to lean on the rails. Although the camera is directed over the railings of the boat from which he is photographing nothing but an empty ocean, the cameraman must envision the scene we have described as if it were actually before him. He should realise that such a foreground scene, shot later on a stage, will occupy at least the lower half of the finished picture. By placing the bevel protractor along the top of the camera, he will find that it is tipped down perhaps 10 degrees, and that the distant horizon is about three-fourths up from the bottom of the picture. This means that the finished picture will include deck action in the lower half, ocean in the next quarter, and sky in the remaining quarter. When the foreground is doubled later on the stage, the camera must be set at the same angle, in this case 10 degrees, for if it were placed horizontally, the picture obtained 4 , a eer