1、_ SMPTE EG*7 94 8357403 000Lb8 358 M SMPTE ENGINEERING GUIDELINE Audio Sync Pulse for 8-mm Type S EG 7-1994 Revision of EG 7-1 989 Cameras, Magnetic Audio Recorders and Rerecording Projectors 1 Scope This guideline specifies the characteristics of the audio sync pulse for 8-mm type S cameras and fil
2、m recorders and for magnetic tape recorders and audio projectors used for transfer of audio records from magnetic tape and film to a magnetic edge stripe on an 8-mm type S print. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provi
3、sions of this guideline. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this guideline are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. ANSIEMP
4、TE 164-1 993, Motion-Picture Film (8-mm Type S) - Magnetic Audio Record - Position, Dimensions and Reproducing Speed NAB Standard for Magnetic Tape Recording and Reproducing (Reel-to-Reel) 3 Terminology 3.1 Camera and projector classes 3.1.1 Class A: Speed controllable (self-resolving) 3.1.2 Class B
5、: Speed uncontrollable 3.2 Sync signal phase 3.2.1 Open shutter sync: Sync occurs while the shutter is open. Page 1 of 2 pages 3.2.2 Closed shutter sync: Sync occurs while the shutter is closed. 4 Camera specifications 4.1 Sync signal The camera shall provide a sync pulse at frame rate (24 fps nomin
6、al) as a voltage pulse, tone burst, or other sync signal. 4.2 Photographic sync mark The photographic sync mark shall be on the edge of the film opposite the sprocket holes and shall be approximately one frame in length. 5 Recorder specifications 5.1 Location of sync signal 5.1.1 Cassette recorder T
7、he signal shall be located on track 4 in accordance with IEC and NAB standards for audio-visual cue pulses. 5.1.2 Reel-to-reel quarter-inch tape recorders The signal shall be located on track 3 (right stereo channel) as specified in NAB Standard MagneticTape Recording and Reproducing (Reel-to-Reel),
8、 Four- Track Stereophonic Recordings Section. 5.1.3 Full-coat film recorders The signal shall be located in the audio record position as specified in ANSI/SMPTE 164 on recorders using 8-mm type S full-coat magnetic stock. Copyright O 1994 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595
9、 W Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved September 1, 1994 EG 7-1994 5.2 Recorded signal level The signal shall be recorded at 10 dB below the reference level of 185 nWb/m at 315 Hz. 6 Projector specifications 6.1 Sync signal The projector shall provide a sync pulse at frame
10、 rate (24 fps nominal) as a voltage pulse or a tone burst. 6.2 Sync signal phase The sync pulse shall be generated immediately following the first shutter opening of a new frame. NOTE - Socket-pin connections. Use of the 8-pin miniature socket (IEC type 130-9-21) is recommended since it offers enoug
11、h connections to accomplish all sync camera require- ments. The connections shall be: Pin 1, Camera chassis ground (sync circuit common) Pin 2, 1 /F (1 -pulse-per-frame) signal Pin 3, 1 /4F (1 -pulse-per-4-frames) signal Pin 4, Motor circuit, positive speed control Pin 5, Motor circuit, negative speed control Pin 6, Tape recorder start/stop normally closed Pin 7, Tape recorder start/stop insulated common Pin 8, Tape recorder start/stop normally open Page 2 of 2 pages
