FIG. 1 - Every photographic subject is illumi¬ nated by a keylight. In this case it is the sun. P reason for the superior quality of Hollywood cinematogra¬ phy lies in the fact that a very system¬ atic method is used in the analysis of each scene and the organization of the illumination elements. The illumination on a scene is usually considered as consisting of certain fun¬ damental elements, each of which has a definite function to perform. The first and most important of these elements is the keylight. Every photographic subject is illumi¬ nated by a keylight. The keylight may be reasonably defined as being the most intense light that is effective on a sub¬ stantial portion of the camera-side of a subject. Outdoors the keylight is usually the sun. Indoors it may be one lamp, or a group of closely assembled lamps, which projects comparatively intense light onto the subject. The relative location of the keylight has a very marked effect on the ap¬ pearance of the subject. This location determines where on the subject the highlights will be located, and where the shadows will lie. (See Figure I, for illustration of effect of keylight on sub¬ ject.) By means of an appropriate location of the keylight the features of a subject may be brought out to best advantage, three dimensional appearance may be enhanced, depth effects may be estab¬ lished, and desirable artistic results may be achieved. The intensity of keylight projected to subject's position usually determines the illumination level for the scene. Other OSSIBLY ONE (Continued on Page 439) FIG. 2-The "Keylite" meter is generally used at subject position and aimed directly at the keylight source - whether sunlight or artificial light. The Significant Keylight Further explorations in science of light measurement has resulted in development of new light meter well suited to needs of particular still and motion picture photographers. By CAPTAIN DON NORWOOD Inventor of the Norwood "Director" Exposure Meter. FIG. 3-Any keylight can be classified as belonging in one of the four location groups shown above. Here sunlight is the most intense light falling on subject. DECEMBER, 1950 AMERICAN CINEMATOGRAPHER * 415