International projectionist (Jan 1959-Dec 1960)

m 2 1 1959 ^INTERNATIONAL PROJECTIONIST Including a special Audio-Visual section relating to the operation and maintenance of A-V equipment in the educational and industrial fields. R. ENTRACHT, Publisher Volume 34 JAMES J. FINN, Editor R. A. MITCHELL, Contributing Editor APRIL 1959 Number 4 Index and Monthly Chat 3 The Videotape Recorder: I. Basic Principles of Magnetic Recording 5 George Goodall Intermittent Movements for 16-mm Projectors ... 10 Robert A. Mitchell Viewing the Projector as an Integral OpticalMechanical System 12 Harold E. Rosenberger Personal Notes 14 The Geneva Intermittent Movement: Its Construction and Action, V 15 A. C. SCHROEDER In the Spotlight 16 Audio-Visual Section 17-21 How to Use a Microphone; Lens Focal Lengths and Screen Sizes; Using Closed-Circuit Tv in Education ; Sylvania's Millionth Tru-Focus Lamp ; Kodak Cavalcade Projector; New Westinghouse Lamp. Obituaries 19 News Notes — Technical Hints — Miscellaneous Items INTERNATIONAL PROJECTIONIST, published monthly by the International Projectionist Publishing Co., Inc., 19 West 44 Street, New York 36, R. A. Entracht, President. Telephone: MUrray Hill 2-2948. Subscription Representatives: AUSTRALIA— McGills, 183 Elizabeth St., Melbourne; NEW ZEALAND— Te Aro Book Depot, Ltd., 64 Courtnay Place, Wellington; ENGLAND and ELSEWHERE— Wm. Dawson & Sons, Ltd., Macklin St., London, W. C. 2. Subscription Rates: United States, Canada, and U. S. Possessions, $3.00 per year (12 issues) and $5.00 for two years (24 issues). Foreign countries: $4.00 per year and $7.00 for two years. Changes of address should be submitted four 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. INTERNATIONA/ PROJECTIONIST assumes no responsibility for personal opinions appearing in signed articles, or for unsolicited articles. Entire contents copyrighted 1959 by INTERNATIONAL PROJECTIONIST PUBLISHING CO., INC. That Ephemeral Projectionist Society CHEMISTRY is an exciting science which in practice often yields wholly unexpected by-products. But language — the chemistry of words — also yields unexpected fruit. Testamentary to this thought are the articles entitled "Viewing the Projector as an Integral Optical-Mechanical System," by Harold E. Rosenberger of Bausch & Lomb Optical Co., now current in these pages. Unwittingly, the learned Mr. Rosenberger touched a nerve center of craft operation when, in discussing the non-integration of the projector, he wrote: "We suggest that the projectionist take steps through his professional societies to relieve himself of the problem he now faces in choosing projection equipment. To illustrate the need for centralized research into the requirements of projection equipment, let us consider just one component of the projection equipment, the projection lens." Now, this is a perfectly reasonable and wholly rational grouping of words — except for one thing: there is no such society. True, there exist professional societies which interest themselves in matters bearing upon the reproduction of picture and sound. But so conglomerate are the applied arts which enter into the audio-visual process that by the time these data are presented in the journals of these reputable, and often stuffy, "engineering" societies, the end product of such activities is so diffused as to be of little practical worth at the transmission (projection) level. Unquestionably Mr. Rosenberger wrote the aforementioned words with the best will in the world, but it would require a long lingering look over his shoulder to discern even a trace of any such "projectionist professional society." "We who have been active in the projection field for 35 years, will recall the existence of such organizations: The American Projection Society and, subsequently, the Projection Advisory Council. But to label these groups "organizations" would be a misnomer because what they actually were was merely a grouping of individuals who, however sincere, could not possibly hope to effectuate the aims so loftily expressed in their articles of organization. The reasons for the ineffectiveness of these groups are many, the salient one being that which is reserved to the knowing. A moment's reflection will occasion no little wonderment as to how a group of craftsmen some 20,000-odd strong could engage in so exacting a practice as the transmission with fidelity of both image and sound to millions of critical viewers daily. Here we have a craft to which machine tolerances of 1/10, 000th inch have been commonplace for the past 50 years — long before the automobile industry even gave thought to such precise production. It is a constant source of amazement to innumerable noncraft personnel how a group of men can deal successfully day in and day out with such trifles (?) as 6-track magnetic sound reproduction, a variety of aperture plates, varying screen sizes, high-intensity arcs ranging up to 180 amperes, high-speed lenses — the list grows long but is nowhere near its end — without the benefit of a centralized source of ready technical data. Perhaps the saddest commentary on the situation is that a nation-wide exhibitor organization, their employers, literally had to beg for craft cooperation in effecting an improved performance level. If the cows in the meadow elected only to chew on their cuds and ignore the grass, there soon would be no milk/ — James J. Finn INTERNATIONAL PROJECTIONIST APRIL 1959