Projection engineering (Jan 1932-Mar 1933)

FEBRUARY, 1932 Page 23 S.M.P.E. TO HOLD SPRING MEETING IN WASHINGTON, D. C. The Society of Motion Picture Engineers will hold its Spring Meeting in Washington, D. C, May 9-12, according to an announcement made by the Board of Governors of the Society. Washington was selected by the Board of Governors following a majority vote for this city by the membership. W. C. Kunzmann, chairman of the convention committee, and O. M. Glunt, chairman of the papers committee, will prepare the program of arrangements for the meeting which will be held during the height of the Washington Bi-Centennial activities. ▲ INTERNATIONALIZING TALKING PICTURES {Concluded from page 7) are to be different versions of the film, care being taken to avoid by a proper choice of words, any actual discrepancy between speech and the movements of the lips. That this is quite feasible was proved in the case of "Nothing New at the Western Front" throughout the whole length of which there is perfect agreement of German speech with the lip movements of English speaking actors. An additional advantage of the rhythmographic process is the fact that the actors, being able to concentrate upon the phonetic parts of the roles, will do much better than in the case of an ordinary talking film record made at the same time as the picture is being produced. A further development of the new method, which is likely soon to materialize, is the "radio talkie," in the course of which the text (read from rhythm bands) is transmitted by radio broadcasting to any number of cinemas communicating among one another and operating in mutual agreement. ▲ CAUSES OF FILM MUTILATION {Concluded from page 8) the film through the machine, all the way to the takeup spindle, a chart was constructed which enumerated in succession all the points in the projector which would admit of study with regard to tension, clearance, and wear, and the bearing which these have upon the mutilation of film and the successful projection of high-quality pictures. This chart is actually a program of the work which the committee has undertaken; to obtain the information requisite for completing the chart, whether or not the values of tension, clearance, and wear found in practice are justified by experience, and are compatible with high quality projection and are economical of film. SIX MORE TECHNICAL QUESTIONS FOR PROJECTIONISTS Correct answers will appear in the March issue of Projection Engineering. 33. State how you would go about setting up for reproduction using sound-on-film. 34. What is the object of the exciting lamp, how is it adjusted? 35. Describe a shunt motor, state how it is constructed. 36. State what you know of the recording of sound-on-disc for use with sound pictures. 37. Give six reasons for lamp not lighting, when using Mazda lamps for projection. 38. How would you locate a grounded coil in generator ? THE ANGSTROM An angstrom is a unit of length which is used to express very short lengths, especially those of wavelengths of light. There are 100 million angstrom units in one centimeter, or ten billion in one meter. Hence a wave of 5,000 angstrom units long is 0.0005 centimeter long. ▲ THE OUTPUT STAGE IN SOUND TRANSMISSION {Concluded from page 13) taken at some arbitrary frequency, though a good rule is to match impedances at the lowest frequency desired. If the amplifier is designed to work with a single loudspeaker, th^ units should be connected as shown in Fig. 14, which duplicates the im pedance of a single loudspeaker. If more than four units are required, the number necessary will increase as the squares of whole numbers, four, nine, sixteen, etc. There should always be as many series groups in parallel as there are single units in each series group. Where it is impossible or impractical to follow these suggestions always have the speakers arranged so that the load impedance is greater than the impedance of a single unit, not less. ▲ TYPES OF SOUND RECORDS {Concluded from page 16) are greater, and there is no possibility that the sound and action will get out of synchronism. It must be understood that the designation "movietone" as applied to this form of composite sound and action print is merely a nickname and does not necessarily mean that the sound was recorded by the Movietone recording system. All of the better theatres are equipped to use either film or disc sound records ; but many of the smaller theatres are equipped as yet for reproduction from hard wax records alone. This is because the disc equipment is not so thoroughly covered by patents as the film equipment, and so small independent companies can manufacture and market disc reproducing equipment at a greatly reduced cost. It is needless to say that often the quality of reproduction obtained with this equipment leaves very much to be desired indeed. The trend seems to indicate conclusively that eventually sound pictures will be released only on movietone prints. Photographs courtesy Universal Pictures Corporation and RKO Studios. ▲ ▲ ▲ Chemical stages in the manufacture of. film. Cdhdase WW« Solution "DOPE" Pthn Supporl Emulsion 1 Finish*1*! Film Courtesy Eastman Kodak Co., Roci-crcr, X. V.