American cinematographer (Jan-Dec 1941)

each other. In other instances, einematographers have utilized Weston meters— especially the new Weston "Master" model — similarly, both with and without modifying aperture-plates. The Technicolor Corporation, as is well known, have their own type of meters, specially adapted from Weston footcandle meters, but used in essentially similar ways. I think it will be generally agreed that while these meters all present considerable advantages, they all suffer from one uniform difficulty: none of them are sufficiently selective. A very slight difference in the positioning or angling of the meter will make it give greatly different readings. It may scan more or less of the beam of the keylight, or even be further thrown off by including some of the "filler" or crosslighting illumination. It is entirely possible for two individuals to take readings on the same scene with two meters which on the test-bench check with each other perfectly, and — simply due to slight differences in the way they position their instruments — obtain noticeably different light-value readings. With this in mind, I have recently developed a meter which in the opinion of engineering experts from Technicolor, Eastman, and other organizations, as well as in my own opinion, appears to mark a worthwhile stride toward the elimination of these errors. The foundation of the meter is a standard Weston "Master" exposuremeter. The only permanent modification made in the meter itself is fitting its case with two small metal rails upon which my fitting is mounted. Sliding into place along these rails is a dovetailed metal lens-mount holding an old 2-inch camera-lens. With the meter's hinged light-baffle hinged out of the way to permit low-brightness readings, this objective is slid into place 1 over the meter's photoelectric cell. Extending forward some eight or nine I inches from this fitting is a small metal | bar. At the outer end of the bar is mounted a white target-field about three inches square, upon which the lens is focused. This target carries a sheet of matte-white cardboard identical with that used in the well-known Eastman color-temperature meter. It is mounted 'so that it may be inclined to one side or the other of the meter-lens axis, to I avoid reading in the meter's shadow. In ! practice, about a 45-degree inclination is used. In use, the meter is taken to subjectposition and placed so that the white "' target-card is illuminated by the keylight, and the reading is taken. It is quite easy to determine visually when 1 the card is in the key-light's beam. Due ,| to the fact that the lens' field is confined solely to the area of the targetcard, and that the lens is also quite deeply hooded, the meter can ordinarily read only on the key-light. Experience has shown, too, that unlike conventional meters, minor changes in the angle of the device do not produce disproportionate changes in the meter's reading. For my own use, I have further simplified thing's by placing a strip of white tape over the meter's dial, concealing the usual calibrations, and bearing two arbitrary ones directly related to my own work. One of them represents the 500 foot-candle key-light level preferred for Technicolor. The other represents the somewhat lower key-light level I find preferable for black-and-white. It would of course be entirely possible to dispense with these calibrations, and arbitrarily use whatever points on the meter's original scales might be found suitable; in fact, for the free-lance cinematographer going from one studio or laboratory's processing standards to those of another, this might be preferable. For my own use, however, I find that the two-point scale makes for quicker and more convenient use. An essential feature of this adaptation is the fact that it does not make any permanent change in the meter itself. Most of us, when working on ex terior scenes, use our meters in the conventional way, as exposure-meters for overall reflected-light readings. With this device, all that is necessary is to slide the auxiliary lens and target off, and the basic Weston meter is ready for use, quite unchanged. While this adaptation of a familiar, commercially-available meter probably does not represent the ultimate in lightmeasuring instruments for studio camerawork, and can — and probably will — be improved as other cinematographers and engineers experiment with its basic principle, I feel that it does at least mark a forward step in our search for a simple, selective and uniformly accurate meter for professional use in studio interior lighting. It is with the hope that out of it may grow further advances in the design and use of meters to simplify our lighting problems, rather than with any desire for personal credit, that I have taken this means of bringing it to the attention of the industry. Two views of Freund's meter: Above, assembled; below, disassembled. On opposite page. Freund is shown making a reading with the meter while filming Elsanor Powell. Photos by Virgil Apger. American Cinematographer • April, l'.ui 159