Movie Makers (Jan-Dec 1952)

326 Incident light meters indoors: 1 LEO J. HEFFERNAN, FACL FIG. 1: Hold the meter close to the subject and point it at the camera. This gives correct exposure for average toned subjects. FIG. 2: Check readings are made from other side of set to assure even lighting. Note crouched, to-one-side position of operator. FIG. 3: For even texture, background lighting should balance in foot candles the reading on foreground. Variations are for drama. WHEN filming indoors by artificial light, a movie maker can shoot with confidence if he is using an incident light type of exposure meter. He simply holds the meter close to the subject and points it at the camera. The lens diaphragm and shutter speed settings indicated by the meter will then be correct for average-toned subjects (see Fig. 1). The procedure is the same for lighter or darker than average objects, except that a slight compensation is made in a way which will be discussed later. Now, there is a reason why the operation of an incident light meter is simple and its results accurate. Filmers who have used reflected light meters know that these are pointed at the subject. However, since subject brightness varies over a wide range, care must be exercised to find an average-toned area at which to point such a meter. It is even recommended that a gray card be carried along on filming excursions, or used at home, to provide an area of the correct tone. With an incident light meter these problems vanish. For the source of illumination is then measured as a basis for determining exposure, and the meter will function properly regardless of how variegated the scene tones may be. FACTORS AFFECTING INDOOR USE Using an incident light meter indoors differs in some ways from its use outdoors (see Movie Makers, February, 1952), where the single source of illumination is the sun. Indoors there are a number of light sources, and it is after these lights are arranged as desired that meter readings are made. Of necessity, amateur movie lights are set up quite close to the actors or objects being photographed; and this means that the light will be intense on near objects and much weaker upon those farther away. This must be kept in mind when using the meter, for it must be held in the same plane as the subject — even if it is necessary to move an object or to ask an actor to shift his position as the reading is made. The actinic strength of a light beam is one quarter as great when the distance from lamp to subject is doubled, so it can be seen that holding the meter nearer or farther away from the light source will affeci the reading. Reflections from clothing also effect the reading, so that the meter should be held at arm's length rather than close to the body. Furthermore, the filmer will want to stand to the side of the subject, or assume a squatting position, so that his body and head will not block the lights (see Fig. 2). ONLY FRONT LIGHTS COUNT Normally, there will be a main light consisting of the strongest available light source, and a fill light, weaker in intensity and located near the camera. (In the illustrations, two reflector-flood lamps close together are the main light, and a T-20 lamp in reflector is the fill light. Both of these light sources are located in front of the actors.) Only lights which are in front of the subject should be considered when the exposure is calculated; the back lighting is ignored, as is the light shining on objects behind the subject, such as background walls, etc. These lights may be turned on or not, for they will not affect the reading with an incident light type of meter.