International projectionist (Jan 1961-Dec 1962)

bon-arc lamps aided, in the case of some drive-ins and other large theatres, by the use of American 5-to-1 high-speed intermittent mo*" which increase shutter I''' sion from the stair'' 65 per tou. Average Screen Widths A recent survey by the Motion ljiv_ture Research Council indicates that the average width of American indoor-theatre screens is 35 feet, and that the average width of American drive-in screens is 90 feet, or a little more. As a matter of fact, 6 per cent of all the drive-ins surveyed have screens ranging from 115 to 120 feet in width, while fully 4 per cent have screens wider than 120 feet. How do the sizes of European screens compare with these? "The average theatre on the European continent," we are told, "is far smaller than the average theatre in the United States. In Holland, for example, the average is less than 700 seats, in Germany less than 600, and in Switzerland about 350 seats." These theatres seldom have screens wider than 25 feet, and probably average 13 feet for regular projection and 18 feet for CinemaScope. Taking 15 feet as the mean width of European screens, and assuming merely for the sake of illustration the use of the same type of screen surface and the same level of illumination, the average American indoor screen requires 5.44 times more light, and the average American drive-in screen 36 times more light, than the average European screen. But to come closer to the realities of the situation, the average brightness prevailing on American indoor screens is more than twice the European, stepping up the American indoor requirement to more than 10.88 times the light required by the average European theatre. American Screens Are Brighter Integration of Research Council survey data reveals that the brightnes of the average American indoor-theatre screen (projector running, without film) is 20.41 footlamberts for nonanamorphic widescreen projection and 21.47 fL for CinemaScope. The brightnes ratio between the two processes is only 1.05, which indicates that aspect ratios less than 1:1.85 are used for standard-print projection in some theatres, less than 1:2.35 for CinemaScope in others, and that the average side-to-center screen-light distribution of 60 per cent tends to minimize the differences in light transmission of apertures of different sizes. All the evidence indicates that the (Continued on Page 16) International Projectionist ® BalCOLD REFLECTORS CUT HEAT INHALE Read this Hollywood test report. "Film gate heat at 1.85 aperture, is 280° F. with silvered reflectors, but only 140° F. with BalCOLD." And look at the benefits when BalCOLD Reflectors cut heat in half: NO FOCUS DRIFT. As much as 5400 feet of film have been run without refocus. Cooler film gate cuts down film bulge — keeps constant focus. GREATER DEPTH OF FIELD. Less film bulge means better background resolution, color fidelity, and clearness of detail. NO END-OF-REEL CONTRACTION. Lens and projector parts can't cool off and contract (thus changing focus) because BalCOLD Reflectors don't let them get hot enough to expand! NO EMULSION PILE-UP. Green film never gets hot enough to leave emulsion coatings on film tracks and shoes. LONGER REFLECTOR LIFE. Theatres all over the country report up to 17 months and more constant, top-quality performance. LONGER FILM LIFE. Theatres report film life doubled with BalCOLD Reflectors. Means a lot when prints cost up to $10,000 ea. Next time you replace silvered reflectors, replace them with BalCOLD — the only reflector whose proven contribution to the advancement of motion picture projection has won for its designers the highly regarded technical award from the Academy of Motion Picture Arts and Sciences. TECHNICAL AWARD to Bausch & Lomb engineers for the development of the BalCOLD Reflector. © A.M.P.A.S. ^r(2 I Academy of Motion Picture Honorary Award (or Optfca ce to the Industry. . , BAUSCH & LOMB INCORPORATED 61614 Bausth St., Rochester 2, N. Y. □ Send me BalCOLD Data Brochure E-35. Name .... Theatre Address City ... Zone State February 1961