International projectionist (Jan-Dec 1947)

©C18 92416 INTERNATIONAL HOECm With Which Is Combined Projection Engineering HENRY B. SELLWOOD, Editor Volume 22 AUGUST 1947 Number 8 Index and Monthly Chat 3 What Makes a Good Loudspeaker? 5 R. S. Lanier Increased Light for 16-mm Projection 8 E. J. Zavesky and W. W. Lozier Historical Development of Sound Film, II 10 E. I. Sponable Trucolor Only Acetate Releases 'til 1948; Splicing and Focusing Data 12 DeVry '12,000' Series 35-mm Sound-Film Projector 14 E. W. D'Arcy Letters to the Editor 16 16-mm Projections 18 Projection Data Charts, IV-B 21 Robert Allen Mitchell Westrex Service Plan Designed to Retain U. S. Lead in World Equipment Market 22 At Your Service 24 In The Spotlight 26 Harry Sherman RCA's New Dual Track, MultiFrequency 35-mm Transmission Test Film 29 Edward Stanko Special Speaker Needs of Theatre Sound Systems .... 30 Personal Notes 36 News Notes Technical Hints Miscellaneous Items Published Monthly by INTERNATIONAL PROJECTIONIST PUBLISHING CO., INC. 19 West 44 Street, New York 18, N. Y. R. A. ENTRACHT, Publisher SUBSCRIPTION REPRESENTATIVES AUSTRALIA: McGills, 183 Elizabeth St., Melbourne NEW ZEALAND: Te Aro Book Depot, Ltd., 64 Courtenay Place, Wellington ENGLAND and DOMINIONS: Wm. Dawson & Sons, Ltd., Macklin St., London, W. C. 2 Yearly Subscription: United States and possessions, $2.50 (two years, $4); Canada and foreign countries, $3; single copies, 30 cents. Changes of address should be submitted two weeks in advance of publication date to insure receipt of current issue. Entered as second-class matter February 8, 1932, at the Post Office at New York, N. Y., under the act of March/ 3, 1879. Entire contents copyrighted 1947 by International Projectionist Publishing Co., Inc. International Projf.ctionist is not responsible for personal opinions appearing in signed articles in its columns. MONTHLY CHAT SOMEHOW and soon the projection field will have to come to grips with the problem posed by the ever-increasing demand for more, and still more, light on the screen. Already acute in many of the larger theatres, some of which have gone to fantastic lengths to obtain more light, the problem will be compounded as the ratio of color films to black-andwhite prints increases. [Preliminary announcements indicate an increase of 25% in color feature releases for the 1947-48 season: 52 Technicolors, 13 Cinecolors, and 12 Trucolors, the latter, from Republic, all to be on acetate stock. Various series of shorts, including Magnacolor units, will round out the color schedule.] Manufacturers of film stock, carbons, arc lamps and projectors are even now huddling and striving feverishly to effect some practical means for countering the inevitable deleterious results of the constantly-rising amperage level. Directly on the spot to take the brunt of the "beefs" certain to ensue as amperages go up are the film stock people, because their product itself is literally on the spot. Few projection people will stop to reason "why" the film buckles; they will be acutely conscious only of the fact that it does. There are many angles (other than the projection) to this problem of adequate screen brightness. Many factors affect the final decision in a given situation, and practically every theatre is a special problem in itself. Pertinent factors warranting careful consideration include the physical characteristics of the auditorium, the type of lamp, the size of carbon, the optical setup, the screen size, the length of throw, accurate positioning of the lamp elements, and the amperage. We italicize the last phrase because amperage is really the point of this little essay. I. P. has ever been the champion of adequate screen light, and we regard the present SMPE standard of 10 ^ 4 foot-lamberts as adequate for the vast majority of theatres. Moreover, we wish to make the following flat statement: Increasing the amperage does not in itself assure an increase in screen illumination, particularly with respect to exceeding the manufacturers' ratings for both lamps and carbons. In fact, increasing the amperage can be definitely harmful in many instances, resulting not infrequently in "washing out" the tone value of a picture, whether black-and-white or color, in the pencilling of the carbons and concomitant alteration in spectral characteristics, in damage to the mechanical parts of the lamphouse, in an increase in flicker, in excessive carbon consumption, and in a waste of current. "What!" will likely be the exclamation of many a projectionist. "Do we understand you to say that we can ever (Continued on page 38) INTERNATIONAL PROJECTIONIST • August 1947