Journal of the Society of Motion Picture Engineers (1930-1949)

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Proposed American Standard 16mm Motion Picture Projector For Use With Monochrome Television Film Chains Operating on Full-Storage Basis (Fourth Draft) PH22.91 P. 5 of 8 pp. 11. Film Capacity and Reel Tension 11.1 The projector shall accommodate reels of any capacity from 400 to 3600 feet which comply with the requirements of Proposed American Standard PH 22.1 1-1952. 1 1 .2 For any reel size in this range, the takeup tension shall at no time be less than 3 ounces nor greater than 10 ounces (hub diameters less than 4.5 inches excepted). 11.3 For any reel size in this range, the braking mechanism on the feed reel shall not cause a tension greater than 3 ounces (hub diameters less than 4.5 inches excepted). 12. Film Life 12.1 After 100 passages through the projector mechanism, film shall exhibit no evidence of damage either visible in the projected picture or audible in the reproduced sound signal. 12.2 In order that a loop of film may be used in this test, renewal of the splice as many times as may be necessary is permitted. 12.3 The film used in this test may and should be carefully selected and lubricated. The projector is not required to pass this test with film which is in inferior condition. 12.4 Passage of a splice in good condition through the mechanism shall not cause serious disturbance, such as loss of loop, nor shall the mechanism cause excessive damage to the splice. 13. Starting Time 13.1 Definition. The interval between applications of power and the attainment of: (a) synchronous operation of the motor and (b) a flutter content in the sound output which is less than the maximum specified in Paragraph 17.2. 13.2 Standard. The starting time shall not exceed 5 seconds. 14. Film Speed 14.1 The nominal speed of projection shall be 24 frames per second. This shall not be interpreted as excluding the use of a 3-2 mechanism. 15. Stopping Distance 15.1 Definition. The length of film that passes through the film gate after removal of power. 15.2 Standard. The stopping distance shall not exceed 3 feet. 16. Manual Drive 16.1 Some readily accessible means shall be provided for slow-speed manual operation of the mechanism as a check on threading, etc. 17. Sound) Scanning System 17.1 Synchronization. The film path distance measured in the direction of travel from the center of the picture aperture to the point to which sound scanning occurs shall be 26 frames — Vi frame. 1 7.2 Mechanical stabilization. The rms value of the total (sum of all frequencies) flutter shall not be greater than 0.25% when using a 3000-cycle flutter test film complying with vhe requirements of American Standard Z22.43— 1946. Film splices shall not cause any serious disturbance in sound stabilization. 17.3 Dimensions of Scanning Aperture. In the plane of optimum focus the scanning light beam shall have a maximum width of 0.0005 inches and a length of 0.071 ± 0.001 inches. (Reference for length: American Standard Z22.41-1946.) NOT APPROVED August 1952 Journal of the SMPTE Vol. 59 149