SMPTE ST 97-2004 Motion-Picture Film (16-mm) - 200-Mil Edge Position - Magnetic Audio Record.pdf

1、 1 Scope This standard specifies the position, dimensions, and reproducing speed of the nominal 0.200-in (5.08-mm) magnetic audio record on 16-mm motion-picture film. 2 Audio record 2.1 The lateral location and width of the magnetic audio record shall be as specified in figure 1 and table 1. 2.2 The

2、 recording shall be made so that the azimuth of the record is at an angle of 90 3 to the reference edge of the film. 2.3 With the direction of travel as shown in figure 1, the magnetic coating is on the surface toward the observer. 3 Reproducing speed The recording shall be made so that the audio re

3、cord will reproduce properly at 24 perforations per second (approximately 36 ft 11 m per minute or 7.2 in 183 mm per second) which is 24 frames per second. Figure 1 Lateral location and width of magnetic audio record Page 1 of 2 pages SMPTE 972004 Revision of ANSMPTE 97-1999 Copyright 2004 by THE SO

4、CIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved November 8, 2004 SMPTE STANDARD for Motion-Picture Film (16-mm) 200-Mil Edge Position Magnetic Audio Record SMPTE 97-2004 Page 2 of 2 pages Table 1 Specifications Dimensions Inches

5、Millimeters A 0.525 0.002 13.34 0.05 B 0.200 0.002 5.08 0.05 Annex A (informative) Additional data A.1 Record width The width of the recorded area must be measured with great care as it enters directly into the calculation of flux per unit track width. When the recording head gap is narrower than th

6、e width of the coating or stripe, as is normal for all motion-picture test films, there is a measurement complication involving both the uncertainties in seeing the track and in determining the recording fringing. If the recording head is available, the track width is best measured indirectly by mea

7、suring the gap width and adding to this dimension twice the thickness of the test record magnetic coating. This correction will usually be 0.0003 in to 0.0006 in (8 m to 15 m). If the recording head is unavailable, the recorded record may be made visible by the use of a carbonyl iron suspension. Car

8、e should be taken to apply the minimum quantity that makes the recording visible, so that the developed image is not wider than the actual recorded area. A.2 Reproducing the head gap width If precision measurements or calibrations are to be made on magnetic audio records made in accordance with this

9、 standard, reproducing head gaps of the same width dimension or wider than the recorded track must be used to prevent edge effects or fringing. A.3 Erase heads Erasing head gaps used to erase the records specified in this standard should be substantially wider than the record specified. A.4 Film bas

10、e The film base used for the audio records conforming to this standard is usually made in accordance with SMPTE 109. A.5 Picture-audio synchronization The film is used for audio records only. Any accompanying picture is on a separate photographic film. When audio records are intended to be used in s

11、ynchronization with pictorial material found on a separate film, the picture-audio relationship should be in accordance with SMPTE RP 25. A.6 Magnetic coating The dimensions of the magnetic coating are not specified, but it is assumed to be wide enough to permit the placement of the audio records in accordance with this standard. Annex B (informative) Bibliography SMPTE 109-2003, Motion-Picture Film (16-mm) Perforated 1R and 2R SMPTE RP 25-1995, Audio and Picture Synchronization on Motion-Picture Film Relative to the Universal Leader for Magnetic and Photographic Records