American cinematographer (Jan-Dec 1946)

The New Norwood Exposure Meter By RALPH A. WOOLSEY and CHARLES H. COLES (Photo Research Corporation) Fig. I. Closeup balanced and exposed according to technique described article. WHEN the Norwood Director meter was first introduced to the studio cameramen in Hollywood a few years ago, its radically new design elicited some raised eyebrows and skepti¬ cal comments. However, the continued success of its users in achieving accurate exposure control has stimulated a wider and wider use of the meter until now it may be found in studios all over the world. Constructed of an improved translu¬ cent material, the patented hemispherical light-collector is now known as the “Photosphere.” The designers of the meter have greatly increased its scope of usefulness by making the Photosphere interchangeable with two accessory lightcollectors, so that the instrument now performs the multiple functions of an incident-light exposure meter, a light intensity (foot-candle) meter, and a brightness-range meter. Still the heart of the Norwood Direc¬ tor, the Photosphere simulates the cam¬ era side of any three-dimensional sub¬ ject. In use, therefore, it is simply held near the subject and pointed directly at the camera. In this position it inte¬ grates all the useful photographic illu¬ mination irrespective of the angle at which it strikes the subject. If it hap¬ pens that the indicating pointer is not conveniently in view, the meter body may be rotated around the pivot con¬ necting it to the Photosphere base until the dial faces the observer. This feature is a convenience that cameramen have greatly appreciated. Among its advan¬ tages they have discovered are the elim¬ ination of interference from shadows cast by the user and the ease of making readings in close quarters. The Director shows its supremacy when working under lighting conditions considered unusual or difficult for other methods of exposure determination. En¬ tirely lacking is the uncertainty exper¬ ienced with the varying indications of most meters as they are tilted slightly one way or the other. Owing to its unique design, the Director has elimin¬ ated this critical directional sensitivity. The pointer holds its position without fluctuation even when side on backlight¬ ing is encountered since no special pre¬ cautions are necessary to assure accurate reading. The Photosphere integrates light from any direction with equal ef¬ fectiveness. It is in color photography that the Norwood Director displays its accuracy and consistency to the greatest extent. It measures, integrates and evaluates incident light so that the flesh tones of a subject will always appear natural as long as the light has the proper colortemperature. Because these tones are the most critical, their accurate reproduction will assue fidelity in all other colors in the picture. Even though the background is light or dark, flesh tones will always appear correct. In addition to determining the over¬ all exposure, the new Director measures other important photographic factors by means of interchanging the photosphere with special light-collectors. Lighting contrast control is facilitated by the use of the “Photodisk” which provides illu¬ mination measurement over a range of 0-10,000 foot-candles, assuring a quick, accurate means for measuring the in¬ tensity of key or other light-sources. A reflected-light attachment, the “Pho¬ togrid,” is used with the Norwood Direc¬ tor for brightness measurements or brightness range control. The Photo¬ grid may also be used if it is possible to read the incident light for exposure determination. Two models of the Director are now in use. The Cine model, designed for motion picture photography, is calibrated directly in f-stops from f/1.4 to f/22 for a constant shutter speed. Adjustment for various emulsion speeds is provided by interchangeable perforated metal slides which are inserted behind the lightcollector to control the light reaching the photoelectric cell. A computer allows use of the meter for still photography by facilitating the selection of shutter and 254 July, 1946 • American Cinematographer