International projectionist (Jan 1959-Dec 1960)

irom the ticker through the projector, the quotations move across the screen as the ticker operates. The lens is nearly a foot in diameter, over one foot in length and weighs 65 pounds. It has a focal length of 38 inches with an F:4 speed. The lens provides a sharp image and has been especially designed to compete with the intense sunlight that usually streams through the windows high above the Exchange floor. B&L also designed and installed special lenses for all of the projectors in the Bond area of the Exchange. Harwald's Open House and A-V Workshop, Feb. 26-28 The Harwald Co., 1245 Chicago Ave., Evanston, 111., will hold its annual Open House and Audio-Visual Workshop in the company's plant February 26-28. This year's session will feature speeches by authorities representing different aspects of the audiovisual field. Also, certain periods will be devoted to informal discussions and presentations of case histories and new developments. The Open House and Workshop should prove a valuable opportunity to meet and exchange ideas. Harwald has been manufacturing A-V and professional film-handling equipment since 1946. NCC Double-Tapered Carbon Extensive field tests in motion picture projection rooms throughout the country during the past three years have proved the technical superiority of larger negative arc carbons with doubletapered ends. According to arc carbon engineers of National Carbon Company, the new design makes possible a much faster initial "burn-in" period and more steady arc operation. The establishment of a stable arc at ugher currents much more quickly than van previously possible with standard 1 -Original Taper -2Double Taper ing effect of perspective distorts the picture excessively at extreme viewing angles. National Carbon double-cored negative. Highly "Directional" Screens N.5.G. single-taper carbons has been accomplished by adding an additional taper to the already tapered end of the largersized negative carbons. Available in the five larger sizes of "Orotip" brand cored negative carbons — the V2-, 7/16-, %-, 11/32-, and 5/16-inch diameters — the double-tapered negative carbon is priced no higher than its single-tapered predecessor and has gained industry-wide acceptance. National Carbon Co. is currently offering, free of charge, its carbon arc bulletins, together with a handsome three-ring binder. PROJECTION SCREENS FOR 16-MM SHOWINGS {Continued from page 8) screen sizes, may be used independently of Table III. The plain white, or matte, screen is preferred for general school use because of its fine, smooth surface and uniform distribution of light over a wide viewing area — the average classroom, for example. Modern unperforated matte screens reflect from 85 to 90% of the light when the white surface is fresh and unsoiled. As shown in Fig. 2, different types of screen exhibit widely different brightnesses when viewed from different angles. The matte screen has the most uniform distribution characteristics, but a slight sheen increases center-line reflectivity to nearly 100%. The angle of view should not exceed 40 degrees from the center line on each side when a matte screen is used (Fig. 3) because the foreshorten OUR PROJECTORS DESERVE THE VERY BEST Highly "directional" screens, such as the glass-beaded and aluminum-surfaced ("silver") types, are not satisfactory for general use. Their apparent reflectivity may exceed 400%. on the center line, and yet be as low as 45% at a 40-degree viewing angle. Even at a 15-degree angle, the picture brightness on a beaded screen is only A CRON-O-MATIC FULLY AUTOMATIC CARBON SAVER will save you an average of $400 a year. Use up positive carbon stubs of any length, without preparation. When the stub is entirely consumed the new carbon goes into use without affecting the lamp operation in any way. Burning stubs of average lengths (3Vi") down to Va", saves you 22.2% on your carbon bill. PROJECTOR PARTS BY LaVezzi Machine Works WEST LAKE ST. • CHICAGO 4 4, III. Designed for use with Ashcraft "D" or "E", Brenkert-Enarc, Peerless Magnarc, or Strong Mogul projection lamps. If your dealer can't supply you, order direct. Only $42.50 PAYNE PRODUCTS CO. (Cron-O-Matic Division) 2454 W. Stadium Blvd., Ann Arbor, Mich. ( ) Send literature on the Cron-O-Matic Ship Cron-O-Matic ( ) C.O.D. inc. pos/age. ( ) Remittance herewith NAME THEATRE STREET CITY & STATE Export: Frazar & Hansen, Ltd. San Francisco, New York, Los Angeles INTERNATIONAL PROJECTIONIST FEBRUARY 1959 25