1、SMPTE RECOMMENDED PRACTICE RP 68-2002 Revision of RP 68-1997 S mxificat ions fs r Buzz-Trac k Test Film for 35-mm Motion-Picture Photog rap hic Audio Reproducers Page 1 of 2 1 Scope This practice specifies a test film for checking the lateral position of the audio scanning beam in 35-mm motion-pictu
2、re photographic audio reproducers. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this practice. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agr
3、eements based on this practice are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. ANSVSMPTE 139-1 996, Motion-Picture Film (35-mm) - Perforated KS SMPTE 223M-2001, Motion-Picture Film - Safety Film 3 Test Film 3.1 The test film shall h
4、ave originally recorded 300- and 1000-Hz signal tracks on opposite sides of the central exposed strip as shown in figure 1. 3.2 The position of the tracks shall be in accordance with the dimensions given in table 1. 3.3 The exposed portions of the signal track shall have a minimum density of 1.4 and
5、 the unexposed portions of the signal track shall be nominally clear. 4 Film stock The film stock, preferably polyester, shall be splice-free, of the low-shrinkage, safety type in accordance with SMPTE 223M and cut and perforated in accordance with long-pitch dimensions specified in ANSVSMPTE 139. 5
6、 Identification Each test film shall be identified by a suitable marking printed lengthwise in the picture area. The spacing between consecutive marks shall be approximately 12 in (30 cm). NOTE-Atestfilmconfomingtothis practiceis availablefrom the Society of Motion Picture and Television Engineers.
7、Copyright O 2002 by tTHE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved July 26,2002 RP 68-2002 UNIFORMLY OPAQUE STRIP f- 300 Ht 1000 Hz c REF ER E NCE EDGE Figure 1 - Signal tracks Table 1 - Dimensions D me nc io ns Inches Millimeters IA IB + 0.000 o*286 - 0.001 + 0.001 o*2oo - 0.000 + 0.00 726 - 0.03 + 0.03 5.08 - 0.00 C 0.012 min 0.30 min D 0.012 min 0.30 min Page 2 of 2 pages
