International projectionist (Jan-Dec 1954)

measurement. Just be patient with us. The rotating projector shutter cuts the light approximately in half; and if you divide 45 by 2, the result is 22.5 foot-lamberts. That's pretty close to our estimate of 22.3 foot-lamberts, don't you think? Your value of 43 foot-lamberts was measured without the shutter running! How Light Is Measured All screen light measurements are made that way because the light-meters used don't work accurately with flickering light. But the Strong people divide their direct measurement by 2. Now suppose that Strong and you swapped lamps. Your lamp (with its water jacket and uncoated carbons) would give only 8.0 foot-lamberts at the center of Strong's white screen. The Strong Super "135" lamp would give 42.2 foot-lamberts at the center of your aluminum screen when the shutter is running, or 84.4 foot-lamberts when the shutter isn't running. Satisfied that we had our facts straight? No? Well then consider this. At a 45° viewing angle, the reflectivity of an aluminum screen drops to about 36%, resulting in a screen-center brightness in your theatre of only 3.3 foot-lamberts. Such an extreme angle has little practical significance in long, narrow theatres; but even at a 35° angle (aluminum-screen reflectivity 60%) center-brightness has a value in your theatre of 5.6 footlamberts, considerably below East Coast SMPTE standards. Don't be dazzled by the flood of light that your type of screen throws straight forward like a mirror! For All Viewing Angles With a white screen, however, the brightness remains the same from all viewing angles; and this is why matte screens are mandatory in wide theatres. To use a white screen in your theatre, having the same size as your present screen, you would certainly need more powerful lamps than your present ones. To mention but two out of several makes, the Strong Super "135" burning 135 amps, and the EQUIPMENT & SUPPLIES ^^ /-/if/P/ Theatre /ifeecf! Peerless Hy-Candescent burning 185 amps, both give 16,000 lumens with the shutter running. That's the way the situation looks from here on the East Coast. Appreciation To the editor of IP: I have renewed my subscription to the International Projectionist for a further period of two years. Thank you very much for a magazine that concentrates on giving all the information on the new types of screen presentation and not on the art of selling ice cream. Please note change of address. L. Coulter 22 South Bank, Long Ditton Surrey, England. Westinghouse Sales Film Varied motion picture techniques are being utilized by Westinghouse Corp. in a cross-country tour of a new sales show designed to explain the advantages of modernizing electrical equipment. A 21-foot translucent screen, backed by two motion picture projectors, three slide projectors and two speakers is being used. Showings will be in color, with motion picture scenes blending into slides, and vice versa, as the change in technique suits the sales story. Units of the lA are being urged to contact local Westinghouse outlets for the dates of showings. "GWTW" Still Breaking Records Reissued and playing Loew's State Theatre, N. Y. City, "Gone With the Wind" in its first eight days outgrossed every M-G-M picture that has played there. Similar terrific grosses are being chalked up country-wide, with M-G-M expecting to net $10,000,000 for this trip around the country. Foreign Production Woes Cited Foreign production location jaunts pay off only when American crews go along, according to various directors recently returned from overseas picturemaking assignments. Major blame for the cancellation of some recent American efforts in foreign climes after production was underway is attributed to faulty budget and schedule estimates which did not take into account the fact RCA Theatre Service engineers are on the job with the type of sound service your theatre system needs. Optical or stereophonic sound ... there's no problem too tough for these experts who are backed by the vast technical resources of the Radio Corporation of America. Prompt, dependable RCA Theatre Service has played a top supporting role with exhibitors throughout the nation for more than 25 years! RCA Service Company, Inc. @ A Radio Corporation of America Subsidiary Camden, N. J. INTERNATIONAL PROJECTIONIST • AUGUST 1954 31