International projectionist (Jan 1963-June 1965)

of the arc itself and of the optical system used to project the light. Thus there are facilities at the Parma research laboratory of National Carhon to measure the brightness and color of the arc crater, as well as for projecting motion pictures in a theatresize auditorium to test the complete -\<tem under normal operating conditions. In measuring the color of a carbon arc. light from the crater is received on a diffusing plate in front of the -lit of a recording spectro-radiometer. Light enters the ?lit. and a grating inside separates the component colors of the white light that enters. The instrument automatically measures the amount of each color present and records the figures on a chart that -hows the amount of energy present at each wavelength throughout the \ i-ihle spectrum. The light meters seen in the background measure the intensity of the projected beam to determine the distribution efficienc) of a lamp's optical s\slcm as well as the overall light output. History of the Carbon Arc In the earliest days of the motion picture industry, a light source was coupled to a projector for "screen projection for an audience of main people." The initial light source used a block of calcite. hut it was soon replaced by the carhon arc. Through the years, technological advances in the art of motion picture production brought developments such as "talkie-."' adding a sound tract to film and creating problems both of quiet studio lamps and of silent projection. The advent of color film increased film density, calling for a source of light to illuminate a scene and project an image through film with onlj onetenth the speed of black-and-white film, while matching the color balance of the sun. Drive-in theatres were built with beam throws more than MO feet long, and wide-screen systems increased lateral dimensions to as much as 150 feet. Even with all projected light passing through an aperature the size of a postage stamp, the high levels of screen brilliance were made possible by the carbon arc meeting these and other challenges. IP Projectionist Develops New Device for Carbon-Saving NEVA l ORK — The Master carbon saver has been developed by an IA projectionist "who spent 50 years in a projection booth." Distributed by Master Specialty Products. 200 West 72nd St., New York 23. N. Y.. the carbon saver is also available at the atre supply dealers. Decreasing present projection cost by decreasing carbon waste with the Master saver is claimed, allowing the projectionist to "relax with freedom from fear of show interruption or arc disturbance." The carbon saver is made of high grade heat-resistant steel, containing no springs, screws, bolts, nuts or carbon grinding, the manufacturer states. The carbon is tapped into the carbon saver by "precision taper." The carbon saver is made for Suprex non-rotating arc lamps and also for the rotating type, designed to feed itself into the positive contacts. The Master carbon saver is available for delivery on the Strong high intensity rotating. Ashcraft Super Power rotating, Super Cinex, Core-Lite and Peerless Hy-Candescent rotating arc lamp. Suprex universal nonrotating type for high intensity. Sizes 6. 7. o. 9mm for the Suprex type and 10, 11, 13.6 for the rotating lamp. S3. 50 each: 13.6mm. $4.50 each. iP £ * HIGHEST SPEED IN PROJECTION Kollmorgen lenses rate tops in the motion picture industry. Used exclusively with Cinerama, they are standard equipment in more than 707c of American theaters. High light uniformity and less light loss on the screen — the whole screen — are typical of the outstanding performance of super snaplite" lenses. Other advantages that add up to superior screening with super snaplite are: Wire sharp contrast Uniform illumination Crystal clarity Wide range of focal lengths Sealed construction Bulletin 222 describes Kollmorgen lenses in detail. See your equipment dealer, or write us direct. CORPORATION NORTHAMPTON, MASSACHUSETTS International Projectionist August, 1963 13