Movie Makers (Jan-Dec 1952)

46 INCIDENTALLY SPEAKING... In which MOVIE MAKERS exposure expert explains and illustrates the case for the incident light meter Last July and August, in a two-part article called "You and Your Meter," Movie Makers analyzed and answered the basic problems of using the reflected-light type of exposure meter. Currently, in order to examine fairly both sides of the exposure meter picture, we present the same author-photographer ivith his analysis of the incident light meter. — The Editors. IN the judgment of many experienced photographers, the most convenient means of determining correct exposure for black and white as well as color films is to be found in the use of the incident light exposure meter. And perhaps this judgment is increasingly borne out by the types of meters currently being offered. For today all of the major meters on the market provide, either directly or via an adapter, for incident light readings. Generally speaking, such a meter is placed in the position occupied by the subject and is pointed toward the camera. The meter is then actuated by the light falling on ( or incident to) the subject, without regard for the relative reflectance of the background or foreground objects. The exposure indicated will be correct for average toned subjects (see Fig. 1 ). ILLUMINATION DETERMINES EXPOSURE In other words, exposure is here determined solely by the intensity of the light illuminating the subject — assuming that the latter is average in tone. You will note that this system is exactly similar to the exposure guides packed with color films and often known as "sky-charts." For these guides deal in such sky conditions as Bright, Hazy, Cloudy Bright, Cloudy Dull and Open Shade — each of them, clearly, a measure of light intensity. But the sky-chart system of exposure estimate concerns itself also with another factor — relative subject bright LEO J. HEFFERNAN, FACL ness or reflectance. And, on occasion, so must the incident light meter — or rather, so must the user of it. LIGHT AND DARK SUBJECTS For when bright colored subjects — or dark colored subjects— occupy a large part of the picture area and are important pictorially, their high (or low) reflectance must be taken into account. For example, large expanses of white sand, snow scenes, bright flowers, white buildings, fair-skinned blonde persons and other similarly light subjects will require % stop less exposure than the meter indicates (see Fig 2). On the other hand, dark brown, maroon, dark blue and black objects, dark foliage and other subjects of low reflectance will look better on the screen if % st°P more exposure is given than the meter calls for (see Fig. 3). But, you will ask: "How will I know when a subject is lighter (or darker) than average?" Well, you come to know by learning; and you come to learning by experience. For the intelligent cameraman will be constantly training his eyes to estimate both the intensity of light conditions and the relative tonal brightness of his subjects. He will, if in doubt, shoot the same scene three times: using first the exposure he thinks is right, then a diaphragm opening Yo stop smaller and finally an opening Yz stop larger than the norm. He may then have to discard two of the shots; but the quality of the perfectly exposed scene more than compensates for the loss. And by this test he has added to his store of exposure experience. MIDPOINT RANGE OF REFERENCE Besides, there are also more exact scales of reference. Specifically, a light colored subject is one which is more FIG. 1 (left): Normal use of incident meter positions it at subject pointed toward camera. Average subject will read correctly. FIG. 2: Correct rendition of light colored subject, such as the blond below, will call for V2 stop less than the meter indicates.