This standard specifies the necessary conditions for the color and brightness of the screen for projection at the opening door, as well as the necessary conditions for the color and brightness of the surrounding area lighting. This standard also specifies the relative dimensions of the screen and the surrounding area of ​​the screen and the lighting requirements for the surrounding area required for strict evaluation of the color balance and contrast of color films for television. GB/T 19770-2005 Cinema evaluation viewing conditions for films and slides for television Color, brightness and dimensions GB/T19770-2005 Standard download decompression password: www.bzxz.net
This standard specifies the necessary conditions for the color and brightness of the screen for projection at the opening door, as well as the necessary conditions for the color and brightness of the surrounding area lighting. This standard also specifies the relative dimensions of the screen and the surrounding area of ​​the screen and the lighting requirements for the surrounding area required for strict evaluation of the color balance and contrast of color films for television.

IC5 37. 060. 20
National Standard of the People's Republic of China
CB/T 197702005
Cincmatography-Viewing conditions for the evaluation of films and slides for televisionColours.luminances and dimensions(1S0 6035:1983.M0D)
Published on 2005-05-20
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Administration of Standardization of the People's Republic of China
Implemented on 2005-12-01
GB/T 19770-2005
This standard is modified and adopts 1S0623.5:1983 "Movie evaluation - Viewing conditions for films and slides for television - Colour, brightness and size" (English version)
The main differences between this standard and 106035:1983 are: · The foreword has been rewritten;www.bzxz.net
——Introduction has been added to the normative references: some international references in Chapter 2 "Normative references" have been changed to the corresponding national standards;... Figures have been numbered and titles have been added; - The captions in the table have been changed to the legends of Figure 1;
· The examples in A.1.1 and A.2.2 have been deleted; the item number of A.3.1 has been deleted;
Appendix A of this standard is a normative appendix
This standard is proposed by the State Administration of Radio, Film and Television, and is under the jurisdiction of the China Film Science and Technology Research Institute, which drafted this standard. The main drafter of this standard is Gu Xintai
1 Range
Movie Evaluation Television Film and Lighting Viewing Conditions Color, Brightness and Size
GB/T 19770—2005
, 1 This standard defines the necessary conditions for the color and brightness of the screen for projection at the film opening, as well as the necessary conditions for the color and brightness of the surrounding area lighting.
This standard also specifies the relative size of the screen and the surrounding area of ​​the screen and the lighting requirements for the surrounding area for strict evaluation of the color balance and contrast of color films for television.
1.2 This standard also recommends the conditions of the viewing room that can accommodate a large number of viewers 2 Normative References
The clauses in the following documents become the clauses of this standard through reference in this standard. For any dated referenced documents, all subsequent amendments (excluding errors) or revisions are not applicable to this standard. However, parties that have reached an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced documents, the latest versions are applicable to this standard. G:B/14645—1994 Screen brightness for indoor cinemas and appraisal projection rooms (E41S0)2910:1990)1S06036:1995 Color films and slides for motion picture and television broadcasting Density 3 Color and brightness of open-door projection
3.1 Although the color temperature of white ultimately restored in television systems is D% or illuminant C, the chromaticity and spectral distribution of the screen should be close to the black body nominal 5400K. 5000K to 6500K are all within the acceptable range, but 5400K is preferred if possible. 3.2 The color characteristics of the screen described in 3.1 depend on the chromatic distribution characteristics of the projector light source and the reflective characteristics of the screen (see Appendix A.1.1).
3.3 The use of a low-reflectivity or directional screen is helpful in controlling the illumination of the visible area around the screen. 3.4 Measured in accordance with the provisions of GB/T 4645-1994, the screen brightness for open-door projection should be 137 cd/m2 and 13.7 cd/m2 (40ftL and 4ftL). This brightness will produce a white light brightness of approximately 68 cd/m2 (20ftL) when projecting films that comply with the provisions of IS06036:1996, which roughly corresponds to the peak white level on a color television monitor. 3.5 The brightness at a position 5% of the screen width along the horizontal axis from the edge of the screen should be 90% to 10% of the brightness at the center of the screen. 3.6 If a directional screen is used, the audience should be concentrated in an area where the brightness tolerance is within the allowable range. 4 Screen size
4.1 The size of the screen should be such that the distance from the audience to the screen is equal to four to six times the height of the screen. The screen size should be small enough so that the area of ​​the screen periphery that can be seen is approximately equal to eight times the screen area (see Figure 1). GB/T19770—2005
Jiang: The relative proportions of the dimensions of each part are as follows; H-- 1.co..:3.0...-1.33...-.co Figure 4. Relationship between the area of ​​the area around the screen and the area of ​​the screen 4.2 The aspect ratio of the screen should be 1.33:1
5 Lighting around the screen
5.1 The lighting around the screen refers to the light that can reach the screen, excluding the light of the screen. 5.2 The area of ​​the fixed lighting around the screen should preferably not be less than about eight times the screen weight (see Figure 1). 5.3 The brightness of the lighting around the screen should be 1/6 to 1/10 of the brightness of the screen for parallel projection (see Appendix A.2.1). 5.4 The color of the lighting in the area surrounding the screen should match the color of the screen at the film gate, with the difference being within 200 K (see Appendix A.2.2).
6 Environmental conditions
6.1 The brightness of the ambient lighting should be negligible compared to the brightness of the screen and the brightness of the lighting surrounding the screen. 6.2 The ambient light projected onto the screen and reflected back into the viewing area should be sufficient, so that the brightness of the ambient lighting projected onto the screen should be less than 3.4 cd/m2 (1 ft2L). To achieve this, low-reflection surfaces should be used. 7 Large audience cinemas
If the above conditions are not met because the viewing space needs to accommodate a large number of audiences, the evaluation and impression of the film characteristics may change. The viewing characteristics described in GB/T4645-1994 are suitable for theaters with large audiences. When viewing under these conditions, users should be reminded that eliminating the lighting area around the screen will reduce the audience's judgment of contrast. A.1 Characteristics of screens and projectors
Appendix A
(Normative information)
Other data
GB/T19770—2005
A.1.1 Arc light sources are used in projectors to obtain satisfactory colors. High-brightness carbon arc lamps generally operate at around 5400K. Ambient lamps operate at around 6000K when new, but will drop to 5000K with age. Another method is to add a blue filter to the projector that uses a lamp light source, which can change the micro-invert value by about 110 units, so that the nominal color temperature changes from about 3500K to 400K. Using a blue glass filter of appropriate thickness can reduce the micro-invert value by 110 units. Gelatin filters are not recommended
The simplest way to verify color temperature is to compare it with a reference known to be 400K using a spectroradiometer. A two- or three-color color temperature meter will not measure the relative results of xenon or other light sources that deviate from the blackbody spectrum. Another method is to use a tungsten light source with a sufficient thickness of blue filter to produce a nominal color temperature of about 400K. A.1.2 The choice of screen material depends on the illumination of the projection light source and the method used to illuminate the screen area: If the projection light source is a tungsten lamp, a filter needs to be added in front of the projection lens to change the color temperature to 5400K. A directional high-gain screen may be needed to provide sufficient screen brightness. If the light source is an incandescent lamp with a light output of about 1001m, a matte white screen can be used. If the illumination is 500Im, a 20% reflectivity charcoal screen can be used. A 20% reflectivity matte chromatic screen and a directional high-gain screen can produce satisfactory blackness on an unlit screen under some ambient light conditions. If the lighting is uniform, the above practice does not exclude a back projection screen.
For aesthetic reasons, the screen can be framed. If a frame is added, its width should preferably not exceed 1% of the picture width. A.2 Lighting environment
A.2.1 To judge the quality of a film, the ideal level of ambient lighting should be roughly the same as the average brightness of the picture. Obviously, it will vary greatly, but in most cases, it should be about 1/5 of the brightness of the white light in the picture. However, in order to give the observer the best judgment of chromaticity and color balance errors, the surrounding area of ​​the screen needs to be higher in brightness, and 1/3 of the white brightness is often used, although observers will experience fatigue if they watch for a long time under such conditions. Ideally, the ambient brightness can be adjusted, but if only a fixed value can be used, it should be between 1/6 and 1/10 of the screen brightness at the film gate.That is, 1/3 to 1/5 of the white brightness of a typical copy. This value can be measured directly, or a non-scattering neutral gray filter of appropriate value can be added in front of the lens to check the relative relationship with the screen brightness. This can make the brightness of the silver attenuate by a certain coefficient, and visually judge whether it matches the illumination of the area around the screen. A.2.2 The color matching of the screen and the environment is very important. A non-scattering neutral gray filter with a density of 0.6 is added in front of the lens, and the matching of the screen and the environment can be judged visually. This is the simplest and most accurate method to verify the color matching. Most importantly, the filter should not introduce color. Metal-coated filters can meet this requirement. The illumination of the surrounding area can be obtained in many ways. It can be a transmissive plate. If the screen itself does not emit light, forward illumination can be used. When using this method, the screen can be placed on a plane in front of the plane of the surrounding area of ​​the screen, so that the plane of the surrounding area of ​​the screen is behind the screen. Alternatively, a mirrored optical device may be used to project light around the screen, with the screen partially blocked by a mask. This can also be achieved when using a directional, high-gain screen, with the appropriate placement of the pre-light. Fluorescent lamps are available everywhere, with a nominal color temperature of 5400K.
4.2.3 If, due to room design limitations, the area around the screen cannot be fully satisfactory in terms of specifications and geometry, the requirements for uniformity of illumination and concentricity with the screen in the area around the screen may be slightly reduced, and the basic performance of the viewing room may still be met. GB/T 19770—2005
Compatibility
Tests have shown that, in darkroom conditions with a larger screen, the print should preferably have the same color balance and density as that of a smaller screen with ambient lighting. However, due to visual adaptation, it is possible that a print that an observer judges to be acceptable in a darkroom may be judged to be less acceptable or completely unacceptable in an environment with ambient lighting.
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