1、SMPTE RP*27=4 94 8357403 0001522 635 SMPTE RECOMMENDED PRACTICE Specifications for an Operational Test Pattern for Checking Jitter, Weave and Travel Ghost in Television Projectors RP 27.4-1994 Revision of RP 27 4-1985 1 Scope This practice specifies the format, dimensions, and optical densities for
2、a test pattern transparency to be used as an operational tool for measurement of tele- vision film projector image stability. 2 Purpose 2.1 Specifications This practice specifies a test film to facilitate day-to- day operational checking of travel ghost, weave, and jitter in 35- and 16-mm television
3、 projectors. 2.1.1 Jitter steps The steps at the top and bottom of the pattern are used for measuring picture jitter vertically. 2.1.2 Weave steps The steps at the right and left of the pattern are used for measuring picture weave horizontally. 2.1.3 Central window The central window or rectangular
4、area in the center of the pattern shall be used for measurement of jitter and weave with a grating pattern or a line selector on an oscilloscope. Page 1 of 4 pages revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edi
5、tion of the standards indicated below. ANSI IT2.19-1990, Photography- Density Measure- ments - Geometric Conditions for Transmission Density ANSI/SMPTE 7-1 994, Motion-Picture Film (1 6-mm) - Camera Aperture Image and Usage ANSVSMPTE 59-1 991, Motion-Picture Film (35-mm) - Camera Aperture Images and
6、 Usage ANSI/SMPTE 96-1 992, Television - 35- and 16-mm Motion-Picture Film and 2x247 Slides - Scanned Area and Photographic Image Area for 4:3 Aspect Ratio ANSI/SMPTE 109-1 992, Motion-Picture Film (1 6-mm) - Perforated 1 R and 2R ANSI/SMPTE 139-1 986 (R1991), Motion-Picture Film (35-mm) - Perforate
7、d KS 4 Format 4.1 Pattern A reproduction of the test pattern is shown in figure I. 3 Normative references 4.2 Window configuration The following standards contain provisions which, through reference in this text, constitute provisions of this practice. At the time of publication, the editions indica
8、ted were valid. All standards are subject to The windows shall be staggered so that any trailing or travel ghosts due to the projector shutter opening early or late can be seen above or below the windows. Copyright O 1994 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Harisdale Ave
9、 White Plains, NY 10607 (914) 761 -1 1 O0 Approved February 1, 1994 RP 27.4-1994 4.3 Pattern identification Figure 1 - Reproduction of test pattern 5.2 Testfilm The identification number of this practice shall appear on the projected image in the area specified in the figures. 5 Dimensions 5.1 Tes
10、t pattern The dimensions of the test pattern shall be as shown in figure 2 and table 1 in percentages of frame height and reproduced with a tolerance of I 2% of the frame height. 5.1.1 Tolerances The camera shall be capable of producing an image positioned in relation to the perforations within I 0.
11、025% of picture height for 35-mm and 2 0.05% of picture height for 16-mm film. The test film shall be a camera original film photo- graphed on high-definition, positive motion-picture stock made in accordance with ANSI/SMPTE 139 and ANSVSMPTE 109. 5.2.1 The camera shall be capable of producing an im
12、age in accordance with style A dimensions specified in ANSVSMPTE 59 and ANSVSMPTE 7. 5.3 Projected and transmitted areas The projected image area is represented by the out- side dimensions of the jitter and weave steps. The television transmitted area is represented by the lines inside the jitter an
13、d weave steps. The area shall be in accordance with ANSVSMPTE 96. Page 2 of 4 pages SMPTE RP*27.4 94 8357403 0003524 408 W E- A 1: ID E F G H J K L M N P Q Dimensions Percent Scanned area height 100.00 Scanned area width Television projector image height Television projector image width Camera image
14、 height Camera image width Line length Half-step width Full-step width Half-step length Full-step length Central window height and width Window height Window width Window spacing in diagonal row Window spacing in horizontal row Location of corner windows 133.3333 11.25 0.25 0.50 1.875 3.75 22.50 5.0
15、0 2.50 3.00 10.00 3.00 RP 27.4-1 994 E P4 NS 01 Il r I 1 o o/o o U I CCE A i Figure 2 - Dimensional drawing of test pattern Table 1 - Specifications Inches Millimeters 35-mm 0.594 0.792 0.61 2 0.81 6 0.631 0.868 0.067 0.0015 0.003 0.01 1 0.022 O. 134 0.030 0.01 5 0.01 8 0.059 0.01 8 .- 16-mm 35-mm 1
16、6-mm 0.276 0.368 0.285 0.380 0.295 0.404 0.031 0.0007 0.0014 0.005 0.01 o 0.062 0.01 4 0.007 0.008 0.028 0.008 - 15.09 7.01 20.12 9.35 15.54 7.24 20.73 9.65 16.03 7.49 22.05 10.26 1.70 0.79 0.038 0.018 0.08 0.036 0.28 0.13 0.56 0.25 3.40 1.57 0.76 0.36 0.38 0.18 0.46 0.20 1.50 0.71 0.46 0.20 Page 3
17、of 4 pages RP 27.4-1994 6 Optical densities 6.1 Optical densities All optical densities shall be measured in accordance with ANSI IT2.19. 6.2 Background The background shall have a density greater than 1.9. 6.3 Windows and surround area The density of the windows and surround area shall be nominally clear. NOTES 1 The emulsion position shall correspond to the one nor- mally used for the specific format. 2 Test material conforming to this practice is available from the Society of Motion Picture and Television Engineers. Page 4 of 4 pages
