1、 SUPTE RP*98 95 8357403 O002003 273 M easu re rn e n t of Screen Luminance in Theaters RP 98-1995 Revision of RP 98-1990 1 Scope This practice specifies the procedure for a complete set of screen luminance measurements in theaters, intended to promote measured luminance uniformity that is widely acc
2、eptable to the audience. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this practice. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based
3、 on this practice are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. ANSVSMPTE 196M-1993, Motion-Picture Film - Indoor Theater and Review Room Projection - Screen Luminance and Viewing Conditions 3 Measurement condltlons Projector opera
4、ting conditions, photometer type, lumi- nance level, spectral distribution, color temperature, stray light, and flicker shall be as specified in ANSVSMPTE 196M. 4 Measurement points on the screen The screen shall be considered as being divided into thirds, both horizontally and vertically; thus, the
5、 screen is considered to be divided into nine equal-size rectangles. The measurement point shall be at the center of each rectangle. Page 1 of 2 pages 5 Measurement locations in the seating area 5.1 There shall be six measurement locations: three in the center row of the theater and three in the rea
6、r row of the theater. 5.2 The three locations within the row specified shall be left edge seat, right edge seat, and center seat. (If the center is an aisle, select the nearest aisle seat.) 5.3 At each measurement location, the photometer shall be at the eye level of the average seated audience (app
7、roximately 1.1 meters above the floor). 6 Measurements Photometer readings shall be taken from each measurement location of each of the nine measure- ment points (a total of 54 readings). 7 Luminance range limits For each of the six measurement locations, the follow- ing shall be true: 7.1 Theater s
8、creen luminance at the screen center shall be between 12 fL and 22 fL. Lumi- nance at the screen sides shall be 75% to 90% of the screen center luminance. Review room screen luminance shall be 16 fL at the screen center. The luminance of the screen sides and corners shall be at least 80% of the scre
9、en center reading. Copyright Q 1995 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 1 O607 (914) 761-1100 Approved June 1,1995 SMPTE RP*8 95 m 8357401 O002002 12T m RP 981995 7.2 The readings of the remaining eight measurement points shall not be gre
10、ater than the reading of the center measurement point. The readings of the four corner measurement points shall not be less than 8 fL. The readings of the remaining four measurement points, Annex A (informative) Additional data Al The use of gain screens can raise luminance levels for most of the au
11、dience and, at the same time, save energy. It should be pointed out, however, that with gain screens, the luminance as seen from front and side seats may not meet the level and distribution specified in ANSWMPTE 196M. This lower luminance may be advantageous for the front seats because flicker can b
12、e objectionable in peripheral vision which is a factor for patrons seated very close to the screen. Annex B (informative) Bibliography SMPTE RP 95-1994, Installation of Gain Screens above, below, left, and right of the center, shall not be tess than 10 fL. 7.3 Excluding the center measurement point,
13、 the remaining eght measurement points shall not differ by more than 4 fL. 82 The rear seats In theaters without balconies normally will be within the luminance values obtained in the three readings in the center row, but more readings can be taken, if necessary, to properly curve and tilt a gain screen to obtain good pictorial quality for the maximum number of theater patrons. See SMPTE RP 95 for guidance on curving gain screens.
