1、SMPTE STANDARD - CAUTION NOTICE: This Standard may be revised or withdrawn at any time. The procedures of the Standard Developer require that action be taken to reaffirm, revise, or withdraw this standard no latar than five years from the date of publication. Purchasers of standards may receive curr
2、ent information on all standards by calling or writing the Standard Developer. Printed in USA. ANSIBMPTE 209M-1996 Revision of ANSIISMPTE 209-1 991 for Motion-Picture Film (8-mm Type S) - Magnetic Audio Records - Recorded Characteristic 1 Scope This standard specifies the recorded characteristic of
3、magnetic audio records on 8-mm type S motion- picture prints and full-coat motion-picture magnetic film conforming to ANSVSMPTE 149, running at the nominal speed of 24 frames (102 mm 4.0 in) per second or 25 frames (106 mm 4.2 in) per second. 2 Recorded characteristics The recorded relative short ci
4、rcuit magnetic flux level versus frequency shall be as given by the following equation: Page 1 of 2 pages where L$ is the recorded relative short circuit mag- netic flux level in decibels; f is the frequency in hertz; TI is the low-frequency time constant of 31 80 ps; Th is the high-frequency time c
5、onstant of 90 ps; and 0.02738 is a constant calculated to make LI$ = O at the reference frequency of 31 5 Hz. The appropriate numerical values of the recorded relative short circuit magnetic flux level, L$, for a series of preferred lM-octave frequencies in hertz are given in table 1. 3 Tolerances M
6、agnetic audio records on the film shall be recorded to the characteristic specified in clause 2 within the tolerances given in figure 1. L American National Standard Copyright 0 19% by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hamdale Ave., White Plains, NY 10607 (914) 761-1100 A
7、pproved March 8, 1996 SMPTE 289M 96 8357483 8882343 850 m ANSVSMPTE 2WM-1996 Table 1 - Relative flux level (Lg) versus frequency 125 I 63 I 50 I I +2 -0 m z W o z W a -2 a -1 O I- -4 -6 Hz dB 50 3.04 63 2.15 80 1.45 1 O0 0.98 125 0.65 160 0.40 200 0.24 250 0.1 1 31 5 0.00 400 - 0.12 500 - 0.26 630 -
8、 0.46 800 - 0.76 1 O00 - 1.17 1250 - 1.73 1600 - 2.57 2000 - 3.55 2500 - 4.74 31 50 - 6.18 4000 - 7.84 5000 - 9.51 6300 -1 1.34 8000 -1 3.29 10 O00 -15.15 3 I50 1 6 300 UPPER LIMIT LOWER LIMIT FOR FULL-COPT RECORDING LOWER LIMIT FOR PRINT RECMIDING I o2 103 104 FREQUENCY (Hz) Figure 1 - Tolerances on recorded levels Annex A (informative) Bibliography ANWSMPTE 149-1 994, Motion-Picture Film (8-mm Type S) - Perforated 1 R Page 2 of 2 pages
