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FIG. 5: Averaging highlight and shadow readings may give incorrect exposure for bright chief subject, as seen here.
the ideal density range in Fig. 2.
The third cause of exposure error is an improper evaluation of the components in a given scene. Many filmers still do not realize that composition and background arrangement play a vital part in exposure calculations.
With these three factors in mind, we may say that, on occasion, a meter can exaggerate, minimize or even prove worthless under extreme conditions.
Let us examine some typical conditions. Front lighted snow will thrust a meter needle to the top of the scale. Yet, if the exposure is set at //16, the resulting heavy, blue-black sky will give the scene a definite midnight effect. The answer, of course, is to back light brilliant snow and use the shadows thus obtained to reduce the bright foreground to the approximate sky density. Expose for the shadows. Note Fig. 3.
At sea, to swing a meter gradually downward from the horizon will cause variations from f/8 to //2.7. The graduating density of the sky, as reflected in the water, is partially responsible. Wave action and highlights accomplish the rest. Note the variation of water density in Fig. 4. How can you accurately expose a yellow dinghy, or canoe, upon such a surface? A visual scale of comparative values — which we will discuss later — is the answer. Exposure would be set for the canoe, disregarding, to a large extent, the water.
The generally accepted theory for sunsets is to open the diaphragm to its maximum. This faulty theory makes no provision for (a) the large variety of atmospheric conditions which affect sun brilliance and (b) the inability to "read" the sun. A filmer, using the visual comparative method, would simplv [Continued on page 150]
FIG. 6: Here dark center subject must give way in exposure to high readings of background. Average would be off.
Informed metering, balanced compositions and a knowledge of light values are all factors in the formula, says this color expert
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DIAG. 1: How background affects exposure is seen above. F/8 from B camera will be pleasing only on figure; f/6.3 from A allows for dark ground, while f/9 from C reduces light sky.
Photoaraphs by Associated Screen Studios
DIAG. 2: Similar changes in exposure result from changes in filmed area of single scene. Medium shot, left, exposes for
snow at f/10; near shot, center, is a balanced exposure at f/8, with closeup, right, exposed mainly for figure at f/6.3.