1、SMPTE 40-2002 SMPTE STANDARD for Motion-Picture Film (35-mm) - Release Prints - Photographic Audio Records Revision of ANSKMPTE 40-1997 Page 1 of 3 pages 1 Scope 1.1 This standard specifies the position, dimensions, and reproducing speed of variable-area and variable-density photographic audio recor
2、ds on 35-mm motion-picture release prints. 1.2 This standard also specifies the longitudinal picture-audio displacement. 2 Audio records The dimensions and location of the audio records shall be as specified in figure 1 and table 1 3 Longitudinal picture-audio displacement 3.1 The audio record on th
3、e film shall be displaced longitudinally from the center of the corresponding picture by a distance of 21 frames f 1/2 frame in the direction of film travel during normal projection. 3.2 Although picture and audio are correctly synchronized with a displacement of 21 frames I 112 frame on the film, n
4、ormal playback of motion pictures occurs in theaters where the relatively slow speed of sound means that the aud-io should precede the picture at the screen if subjectively correct synchronism is to be achieved in the middle of the theater (see annex A). 4 Reproducing speed The recordings shall be m
5、ade so that the audio records will reproduce properly at 96 perforations (18 in 457 mm) per second which is 24 frames per second. NOTES 1 Motion-picture prints conforming to this standard are usually projected in accordance with SMPTE 194. 2 Motion-picture prints conforming to this standard are usua
6、lly made on film made in accordance with long-pitch dimensions specified in ANSVSMPTE 139. 3 Dimensions A and B, describing the printed area of the sound record, are established by SMPTE 11 1, and are shown in table 1 as nominal values for reference only. Copyright Q 2002 by THE SOCIEM OF MOTION PIC
7、NRE AND TELEVISION ENGINEERS 595 W. Hafisdadale Ave., Wie Plains, NY 10607 (914) 761-1100 Approved July 26,2002 SMPTE 40-2002 VARIABLE AREA AND MATTED VARIABLE DENSITY SHADED AREAS OPAQUE ON PRINT TO eE EFFECTIVELY FULL WIDTH VARIABLE DENSITY AREA SCANNED BY REPRODUCER .st * Figure 1 - Dimensions Ta
8、ble 1 - Specifications I Dimensions Inches Millimeters 0.308 nom 0.192 nom 0.205 f 0.001 0.281 i 0.001 + 0.004 - 0.000 + 0.000 - 0.004 0.243 i 0.001 0.084 f 0.001 7.82 nom 4.88 nom 5.21 I 0.03 7.14 I 0.03 + 0.10 + 0.00 6.17 f 0.03 2.13 f 0.03 4.90 - 0.00 7*44 -0.10 Page 2 of 3 pages SMPTE 40-2002 An
9、nex A (informative) Explanatory notes In the average theater, it is necessary to emit the sound pulses before the corresponding picture frame is positioned in the aperture. Since sound travels approximately 1100 ft per second or about 50 ft per frame during the normal projection rate of 24 frames pe
10、r second, the projectionist can place the sound and picture in synchronization in the theater where he wishes by varying the length of the threading path in the projector. For example, if the positioning of frame 21 at the scanning point brings the corresponding picture and sound to the screen and t
11、he speaker at the same instant, then positioning frame 20 at the scanning point would give synchronism at about 50 ft from the screen. Annex B (informative) Bibliography ANSVSMPTE 139-1996, Motion-Picture Film (35-mm) - Perforated KS SMPTE 11 1-2001, Motion-Picture Film (35-mm) - Prints Made on Continuous Contact Printers - Exposed Areas for Picture and Audio SMPTE 194-2002, Motion-Picture Film (35-mm) - Projector Usage - Release Prints Having Four Perforations per Frame Page 3 of 3 pages
