American cinematographer (Jan-Dec 1963)

NEWS for M ITCH ELL CAMERA OWNERS FACTORY SERVICE DIVISION Mitchell cameras from Malaya . . . Hollywood . . . and New York arrive daily, leave promptly in like-new-condition after complete, precision work by Mitchell craftsmen. Special sound test room, critical quality control, original fac¬ tory parts, and speed of service guarantee your satisfaction. NEW MITCHELL VARI-STROKE CONTROL All new Mitchell Studio cameras are factory equipped with the new. . .VariStroke control. Now ... it is available as a modification to all Mitchell NC and BNC cameras! Vari-Stroke con¬ trol provides a convenient means for changing the attitude of the pull¬ down claw on the perforation, and in this manner reducing “film noise” due to changes in film dimensions, to a minimum! Only your old type movement is required. Shipped Air Express prepaid, it will be “up-dated” and returned promptly. Write concerning your accessory and service requirements. For brochures -address the Sales Department. MITCHELL CAMERA CORPORATION 666 W. HARVARD STREET • GLENDALE, CALIF. 521 Fifth Avenue • New York, New York NOW REPRESENTED IN OVER 45 COUNTRIES THROUGHOUT THE WORLD. AGENTS IN YOUR COUNTRY ON REQUEST. Q. My problem concerns making a dolly shot of a static display with a 16mm camera moving at an angle of 90° to subject. Is there a published table that can guide me in computing the correct rate of dolly travel so “ skip¬ ping or strobe effects can be avoided ? Would the Panning Speed Tables in Section 4 of the American Cinematog¬ rapher Manual apply to this type dolly shot where the degree of arc is com¬ puted at the center of travel? Do the 35mm Panning Tables in the Manual apply also to 16mm pho¬ tography? — R. G. T., Ithaca, New York. A.— To our knowledge there is no table presently available that can guide you in avoiding the so-called “skip¬ ping” and strobe effects that often result in a dolly shot such as you pro¬ pose to make. This is because the problem in¬ volved is not only highly mathematical but physiological as well. By that we mean that the size, shape, and edge characteristics of your subject matter must be considered as well as the photographic lighting, and also the screen brightness conditions that will prevail in projection of such a scene. The panning speed recommendations published in the Manual are carefully calculated tables that have been empi¬ rically double-checked in exhaustive tests. It was found, for instance, that for photography at 24 fps, the theo¬ retically established value for the pan¬ ning speed in degrees per second could he increased by a factor of 3, follow¬ ing an evaluation of test shots on the screen. The values, shown in the tables in the Manual are the practical applicable values. It is suggested, therefore, that you first shoot a series of tests of your proposed dolly shot and study them in projection to de¬ termine the most acceptable travel speed for your camera dolly. Question 2 is answered in part above; the panning speed recommen¬ dations in the Manual should apply to your situation if the degree of arc is computed at the center of travel. The answrer to your last question is “yes” — the 35mm panning tables in Section 4 of the Manual apply also to 16mm photography. Physiological studies have shown that the troublesome “skipping” ef Technical Questions and Answers iiiiiiiiiiiiiiiiiiiii | QUESTIONS INVITED | Need professional advice on a g jj picture-making problem, about §j H equipment, film or cinematog§§ raphy? Reader's questions are in j| ■ vited and will be answered by J 1 mail when accompanied by a B U stamped, addressed envelope for B ■ reply. Questions and answers con1 jj sidered of general interest to other J jj readers will be published. Address your questions to theg “Question & Answer Editor," Amer-S §§ /can Cinematographer, P.O. BoxJ H 2230, Hollywood 28, Calif. iiiiiiiiiiiiiiiiiiiii . iiiiiiiiiiiiiiiiiiiii . . . . . uni . . . in . . feet in some dolly shots can be mini¬ mized by giving due consideration to the focal lentgh of the lens used, the degree of shutter opening, the fps speed of the camera — plus the bright¬ ness level of projection regardless of image size. Q.— Can the filter slot in the Bolex Supreme 16mm camera be u-sed in making split-frame shots? — J. K. Do¬ ver, N. J. A.— In order to obtain acceptable split-frame or masking effects with any camera, it is necessary that the mask be positioned at a point far enough ahead of the lens or directly in front of the film plane (in hack of the lens in the camera) to insure the necessary sharp line of demarcation between the two split-frame areas. The filter slot in Bolex cameras is intended solely for use of filters and is purposely located a good distance forward of the film. To produce true professional-like mask or split-frame shots with your Bolex Supreme, we recommend use of the Bolex Matte Box which is designed especially for all Bolex cameras. Q. Is there a way to modify a 35mm Eyemo camera to provide a re¬ flex device that will permit viewing the scene or subject continuously while being photographed? — S. V., New York, N. Y. A.— Camera Equipment Company, New \ork, offers a reflex modifica Continued on Page 82 80 AMERICAN CINEMATOGRAPHER, FEBRUARY, 1963