1、SMPTE RECOMMENDED PRACTICE Screen Luminance Conditions for 8-mm and Viewing RP 51 -1 995 Revision of RP 51-1990 i .e., front projection in a darkened room. This is essentially 16 footlamberts i. 2 fL (55 candelas per square meter r?: 7 cd/rn ). 2 4 Viewing prints for special purposes 4.1 Because of
2、the multitudinous applications of 8-mm prints, they are occasionally intended to be viewed under conditions quite different from Page 1 of 2 pages those defined in ANSI/SMPTE 196M. The most common departures include the following: a) Prints used as a background moving image in the design of a public
3、 place rather than as the focus of a viewers attention as in a movie theater; b) Prints used as a point of purchase (POP) selling tool in retail stores or trade expositions; c) Prints used as a selling or instructional tool in compact, suitcase-style, rear-screen projectors; d) Prints used in airpla
4、ne cabins for entertainment of passengers; e) Prints used in public locations for instruction or entertainment under high ambient-light levels; f) Prints used in the home; g) Prints used for photographic instrumentation data analysis. Experience has shown that modifications to the view- ing conditio
5、ns such as those above usually introduce more stringent limitations upon print density, color balance, etc., such that some prints that would be accepted under the conditions specified in ANSVSMPTE 196M become less satisfactory for those modified viewing conditions. 4.2 Prints intended for special a
6、pplications should be judged in a review room with a screen that simulates the special purpose as closely as possible. Copyright O 1995 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 Approved January 5, 1995 (914) 761-1100 SMPTE RP*51 75 = 835
7、7403 0003826 T23 W RP51-1995 Annex A (informative) Additional data Prints are judged best on the type of screen to be used by the end user. Among the types of flat screens commonly used for 8-mm prints are plastic or glass rear screens, matte white vinyl screens, and lenticular vinyl screens. Specia
8、lly formed screens are also used. The rear support member of these screens will have a concave curvature from side to side only or be curved in two directions; .e., from side to side and from top to bottom. These formed curved screens will have surfaces ranging from silver-colored lithographic foils
9、 to vinyl materials embossed with lenticules. These screens have various gains. Gain is a measure of reflectance. A matte white screen is arbitrarily designated to have a gain of approximately 1 for reference. For accu- rate comparisons, it has been determined that matte white screens have an actual
10、 gain in the range of 0.95 to 0.98. Gain screens (those with a gain above 1) are available as treated screens which are flat as well as those embossed with lenticules. Flat lenticular screens have gains ranging from 2 to as high as 20, depending on the design of the lenticules and the screen materia
11、l used. Flat gain screens which are not len- ticular, such as the pearlescent surface, have gains from 1.2 to 2.5. Special formed screens have gains ranging from 6 to 19 depending on the surface material used (flat or lenticular) and the spherical radius used in the rear support member. Acceptable viewing angles of gain screens decrease in- versely with increasing gain. Page 2 of 2 pages
