1、SMPTE RP*122 93 0 8357YOL 0000197 TLT W SMPTE RECOMMENDED PRACTICE Dimensions of Cemented Splices RP 122-1 993 Revision of RP 122-1983 on 8-mm Type S Motion-Picture Film, Projection Type 1 Scope This practice specifies the dimensions of cemented splices on 8-mm type S motion-picture film primarily i
2、ntended for projection. 2 Dimensions 2.1 The dimensions shall be as given in figure 1 and table I. The position of the splice is defined by dimensions C and D. 2.2 The film width at the splice shall not exceed 8.08 mm (0.31 8 in). If the film has been widened during scraping, the extra material shal
3、l be removed. 2.3 The spliced films shall not be offset by more than 0.05 mm (0.002 in), dimension G, as measured by the difference in the alignment of the reference edge side of the perforation holes on either side of the spliced halves. 2.4 The angle between the respective edges of the spliced fil
4、m shall be 180“ -c 8. Thus, the spliced film shall be aligned to the extent that, when one portion of the film is placed against a straightedge, the other portion will not devi- ate more than 0.35 mm (0.014 in) in 15.2 cm (6 in). Page 1 of 2 pages NOTE - The splice should never cut into or include a
5、 perforation. Table 1 - Dimensions Dimensions Millimeters Inches A 1.40 t 0.20 0.055 I: 0.008 Ai 1.40 t 0.38 0.055 I: 0.015 Bi) 11.53 t 0.03 0.454 2 0.001 C 7.19 t 0.10 0.283 = 0.004 CI 6.48 t 0.18 0.255 I: 0.007 D + 0.03 + 0.001 o228 - 0.004 5.79 - 0.10 Di 6.48 t 0.18 0.255 t 0.007 E 0.30 max 0.012
6、 max G 0.05 max 0.002 max )Dimension B is based on a perforation pitch of 4.23 mm (0.1667 in). Allowance has been made for 0.2% film shrinkage. Copyright Q 1993 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved March 5, 19
7、93 SMPTE RP*122 93 EY 8357401 0000198 956 W RP 122-1 993 II 4 ItA RECOMMENDED SPLICE METHOD -I kpi OPTIONAL SPLICE METHOD OVERALL THICKNESS AT SPLICE G Figure 1 - Splices Annex A (informative) Additional data A.1 Splices for 8-mm type S films have been made narrower than conventional 8-mm splices be
8、cause narrower splices are less conspicuous on the screen and are less likely to affect the usual curvature of the film as it follows the bends in its path through cine machinery. A.2 Dimension B controls the longitudinal registration of the two films being spliced. It is measured to the perforation
9、s that are most commonly used for registration on splicing blocks and to the nearer edges of these perforations be- cause they are the edges generally used. A.3 In figure 1, the splice is arranged with the perforations at the top in order to show them as they appear on most splicers. Bevelled splice
10、s are recommended, especially for films which will be run over magnetic heads. However, if unbevelled overlap splices are made, it is desirable to orient the films in splicing so that a magnetic head scanning the film would, at a splice, drop down onto the trailing film rather than bump up onto it. A.4 The scraped area should be limited as closely as pos- sible to the area covered by the overlapping film, in order to prevent the appearance of a white line on the screen. A.5 Cemented splices are not preferred over taped splices for use in continuous-loop systems. Page 2 of 2 pages
