Motion Picture Herald (Jul-Aug 1943)

August 2 1943 BETTER THEATRES 69 is no need for 100% distribution (sides as bright as center), but in some types of background projection used in motion picture studios, in which a picture is projected from the rear of a translucent screen, it is necessary to have more than 100% distribution in order to produce a picture that is free from a "hot spot" in the center of the screen facing the camera. To obtain this unusually high distribution ratio a special optical setup is required, having a relay condenser system fed by a rotating positive high intensity arc. Answer 4 — It is not always true that the center illumination decreases as the side illumination is increased, even when the arc power remains unchanged. An example of a case in which the center may remain the same when the sides are increased is found where poor distribution is the result of optical misalignment. If the alignment is corrected, the center reading will remain unchanged in spite of the resulting increase in side illumination. An example of an occasion on which the center illumination decreases with an increase in side illumination is that when the crater of the positive carbon is moved toward the face of the reflector or condenser. Answer 5 — Yes, lenses having a small opening in proportion to their focus (known as low relative aperture lenses) generally produce images which are less evenly illuminated than lenses having large openings in proportion to their focus. The extent of this distribution loss depends somewhat upon the optical match of the reflector and lens. The more nearly the relative aperture of the lens and reflector are alike, the less will be the distribution loss from this cause. Reflector Working Distance In One-Kilowatt Lamps Daniel gross, projectionist with the Shapiro & Fineman Circuit of Pennsylvania, writes the following: "I have just read your columns in the June 26th Better Theatres and want you to know how much your writings are enjoyed. Regarding the projectionist who wants to trim the rear shutter blades, the only Strong Utility Arc Lamps I have seen have 11 -Ms-inch reflectors in both the low-intensity and the one-K. W. highintensity models. "In accordance with the Strong instruction manual, the center of the reflector should be about 30 inches from the film aperture. Focus is 4 inches from the center of the reflector to the arc crater. Optical speed is about f :2.5. The mirror is Strong Part No. 4069 Spec. 69. The effective beam size should be smaller than 3% inches, and the covering angle might also be smaller, resulting in narrower blades and more light. "Now is there more than one mirror type and size used in Strong's one-K. W. lamp, or has the projectionist who wrote you been using suprex trims in the Utility low-intensity lamp, which should be set at a distance of approximately 24 inches Photograph from "PHANTOM OF THE OPERA" as Produced by Universal Pictures Co., Inc. GRAND OPERA in Technicolor "PHANTOM OF THE OPERA" is a production to demand the ultimate from projector and sound system. Cameramen Duke Green and Hal Mohr catch dramatic close-up and colorful expanse with artistic naturalness — qualities which DeVRY precision projectors screen with credit to producers and applause from patron. "PHANTOM OF THE OPERA" is a picture to test the range, power and perfection ORCHIDS TO. . . Director: Arthur Luhin . . . Cameramen ■ Duke Green, A.S.C.,& Hal Mohr, A.S.C. . . . Soundmen: Bernard B. Brown & Joe Lapis of DeVRY High Fidelity Sound Systems — to do credit to masterful adaptations of Chopin and Tschaikowsky. DeVRY is proud to build equipment capable of reproducing motion picture triumphs such as Universal's "PHANTOM OF THE OPERA." As peace nears, the farsighted and forthright plan to buy DeVRYS. DeVRY CORPORATION, 1111 Armitage Avenue, Chicago, U. S. A. BOX OFFICE BOOSTERS FOR AUGUST This is the Army — WB . . . Silver Spurs— REP. . . Destroyer (E. G. Robinson) — COL . . . Texas Rangers— PROD Victory Through Air Power— UA . . . The Sky's the Limit — RKO ... So Proudly We Hail— PARA Heaven Can Wait— 20TH-FOX Melody Parade— MONO DuBarry was a Lady — MGM — for Excellence in the Production of Motion Picture Sound Equipment \ Distributors in World's Principal Cities WORLD'S MOST COMPLETE LINE OF MOTION PICTURE SOUND EQUIPMENT the new Seventh Edition— Bluebook of Projection By F. H. RICHARDSON $7-25 POSTPAID The Seventh Edition of this standard textbook on motion picture projection brings to all persons concerned with screening 35 mm. film, up-to-the-minute guidance. Additionally, the Seventh Edition contains four chapters on Theatre Television, prepared for the practical instruction of motion picture projectionists. Send your order to — QUIGLEY BOOKSHOP, 1270 Sixth Avenue, New York