1、 Introduction The Committee on Theatrical Projection Technology decided that, with the availability of appropriate test films, a guideline should be developed to assist those interested in determining the degree of acceptability of image quality regarding the apparent sharpness of the projected imag
2、e. Although factors such as image contrast, color fringing, and image steadiness are not covered, their effect on apparent sharpness should be considered. 1 Scope This guideline specifies the conditions for the determination of image sharpness of 70-, 35-, and 16-mm motion-picture projection systems
3、. It also classifies the practical limits of acceptability of image sharpness when using projector alignment test films (see annex A.2). 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this guideline. At the time of pu
4、blication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this guideline are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. SMPTE 196M-2003, Motion-Picture Film Indoor Theat
5、er and Review Room Projection Screen Luminance and Viewing Conditions SMPTE RP 105-2003, Method for Determining the Degree of Jump and Weave in 70-, 35- and 16-mm Motion-Picture Projected Images 3 Test conditions This guideline is based on the assumption that the classifications specified are those
6、to which the projection system has been adjusted as specified in SMPTE RP 105; and that the screen luminance has been adjusted to be in accord with SMPTE 196M. 4 Definitions 4.1 Resolution is the apparent sharpness determined by the ability of a system to reproduce a specified number of equally spac
7、ed black lines and white spaces in groups which are at right angles to each other. (Resolution is described by counting line pairs, a black line and a white space, as a single unit.) Page 1 of 3 pages EG 5-2003 Revision of EG 5-1994 Copyright 2003 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGI
8、NEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved October 20, 2003 SMPTE ENGINEERING GUIDELINE Projected Image Quality of 70-, 35- and 16-mm Motion- Picture Projection Systems EG 5-2003 Page 2 of 3 pages 4.2 The viewers impression of resolution is related to the apparent si
9、ze of the screen image. The apparent size of the screen image may be divided into three classifications: Large: A large appearing screen image is one which is viewed from a distance of 3.7 screen heights or less (vertical field of vision is 15 or greater). Medium: A medium appearing screen image is
10、one which is viewed from a distance of 3.7 to 5.7 screen heights (vertical field of vision is between 10 and 15). Small: A small appearing screen image is one which is viewed from a distance of greater than 5.7 screen heights (vertical field of vision is 10 or less). 5 Method Project an appropriate
11、test film containing resolution targets calibrated in line pairs per millimeter (see A.2) for each format (lens) being used. Examine the projected image closely (see A.1). Note that horizontal line pairs are sometimes affected by system unsteadiness (jump) to a degree which makes them appear to have
12、 lower resolution. Anamorphic lenses should be adjusted (using the distance ring) to have minimum astigmatism, such that horizontal and vertical lines come into focus at the same focus setting. A line pair is considered to be clearly recognizable when the individual lines in the pattern can be clear
13、ly distinguished and the number of lines seen in the pattern is the same as the number of lines in the original target. 6 Classification For each classification of apparent size of the screen image, the practical minimum limit of acceptability in terms of clearly recognizable lines per millimeter sh
14、all be as specified in table 1. Table 1 Minimum limit of acceptability Lines per millimeter Classification Center Sides 1)Corners Large appearing screen image (Review rooms, premier theaters) 80 56 48 Medium appearing screen image (First-run theaters) 68 56 40 Small appearing screen image 56 48 40 1
15、)Assumes left and right sides equivalent at same focus setting. EG 5-2003 Page 3 of 3 pages Annex A (informative) Additional data A.1 Judgment of screen image resolution must be made from areas closer to the screen than those generally considered the best for viewing and definitely not from the rear
16、 of the theater or projection room. A.2 Appropriate test films are SMPTE 35-PA as specified in SMPTE RP 40, SMPTE 70-PA as specified in SMPTE RP 91, and SMPTE 16-PA as specified in SMPTE RP 82. Annex B (informative) Bibliography SMPTE RP 40-2003, Specifications for 35-mm Projector Alignment and Screen Image Quality Test Film SMPTE RP 82-1990, Specifications for 16-mm Projector Alignment and Screen Image Quality Test Film SMPTE RP 91-2002, Specifications for 70-mm Projector Alignment and Screen Image Quality Test Film
