The main purpose of a movie screen is to evenly disperse projector light onto the surface of the screen. The viewing experience and image quality depend on the screen size, surface material and design features of the installation. All of the above requirements will be discussed later in this article.

Screen size
Screen size is selected and installed taking into account technical specifics of projection equipment, total image area, interior and lighting of the audience, as well as the number and location of seats. Regardless of the projector position in relation to the screen its size is chosen taking into account the following factors:

Horizontal parameters. When determining the width of the screen, it should not be allowed to be smaller than the distance to the first row of spectators or the distance to the last row divided by 6. Cinema screens that differ in width from the above parameters to a greater extent, as a rule, only enhance the viewing experience. However, it is not recommended to place the audience seats closer than half the screen width (or one height).
Vertical Parameters. Projection screen surface shouldn’t be situated lower than 1.2 m from the floor (this rule is not obligatory for halls with sloping floor or tiered arrangement of spectators’ seats – amphitheatre). The actual height of the screen is directly dependent on the width and is determined by the format of the image to be projected most often.

Projection formats of cinema screens
The ratio of width to height of the image is called a format. It is selected on the basis of the material to be projected on the screen. If you do not know exactly what content will be mostly displayed, take into account the characteristics of all the formats to be displayed. The most correct choice in such cases is the screen with the maximum height.

According to the ratio of width to height, the following image formats are distinguished:

Audio-visual (AV – 1:1). It is intended for displaying content from most types of projection equipment. Despite the fact that the equilateral ratio implies a square shape of the displayed image, this format also reproduces wide horizontal frames. AV screens are traditionally made without black edges around the perimeter, except when it is expected that the canvas will be permanently stretched. The format is obsolete, and is now almost never used.
NTSC (4:3 format). Widespread aspect ratio, the use of which is gradually losing relevance, giving way to a wider format models. This aspect ratio was used for displaying television channels or cassette videos (VHS, S-VHS).
HDTV screens (16:9 or 16:10 formats). A more modern format used for satellite or high-definition digital television, as well as DVD movie playback.
Wide Screen (1:1.85 aspect ratio). Literally, Wide Screen. Along with the Cinemascope (2.35:1) format, they are most commonly used in the manufacture of screen surfaces for modern cinemas.

Types of surfaces
A woven or non-woven type fabric is used as the basis for the screen plane. The basis of the textile surface is a non-woven fabric of fiberglass, and sometimes even kevlar. Projection screen properties that make it different from the usual sheet, provided by a reflective layer, which is applied to the base. When choosing a material for the movie screen, first of all consider the configuration of the audience and the specifics of the location of seats.

For vinyl screens, the basis is a roll of PVC, which is welded to the required size and then the necessary reflective coating is applied to it.

Types of movie screen coatings.
It is the optical properties of these surfaces that determine the scope of a particular screen.

Regular matte white (MW or Matt White). This is now the most common type of fabric used for front projection. This is due to the increased brightness and contrast of the projection equipment – even among the budget models. MW-covers should be used in the auditoriums where you need a significant viewing angle (about 170 °) because matte screens provide the most uniform dispersion of luminous flux in a wide viewing angle. Traditionally MW type movie screens have low gain (1.0, 1.2), therefore they are preferably used in rooms that can be completely darkened.
For rooms with diffuse ambient light. Here also dominated by matte-white cloth, but with a pronounced light-amplifying effect. The amplification factor in such screens reaches 1.8, which allows to noticeably increase the brightness of the displayed video content and to perform projection in auditoriums with incomplete darkening. Keep in mind that as the reflection ratio increases, the viewing angle decreases. When using light-amplifying screens for projection, viewers should be positioned within 60° of a perpendicular angle to the screen.
High gain canvases are designed for 3D projection. 3D cinema screens have the highest reflection coefficient (about 2.8 – 3). At the same time the viewing angles are significantly reduced (not more than 40°), but the most important difference between 3D surfaces is their ability to maintain the polarization of the projector’s light output. Plus another requirement – to achieve a quality display requires an ideally smooth plane, which can only be achieved by uniform reinforced stretching of the cloth. This tension is only possible with a fixed installation of a movie screen with a canvas on eyelets or in motorized systems with a system of additional tension of the canvas.
Translucent webs. A separate category of screens where the image is projected on them from the rear side. Such surfaces usually have good brightness and contrast, a rather wide viewing angle (in the best samples it reaches 90°), and if there is an appropriate projector the picture is bright and contrasting even with even larger viewing angles. Reverse projection screens are often used in poorly darkened rooms, and for a more saturated image, particularly the realistic display of black, gray cloth is made, and sometimes – even black. The latter are used as stage backdrops. But they require very bright projectors.

Design features of cinema screens
Screen surfaces in cinemas are installed permanently, which somewhat limits the variants of their design. Most often, modifications with a constant tension on loops or buttons on a stationary frame are used. In multi-purpose halls it is better to install electrically driven screens of larger size.

CONSTANT TENSION SCREENS ON A FIXED FRAME
Inner frame for the fabric on the loops. Since, in such constructions, the frame is completely hidden behind the web, the tensioning tube is approximately 32 cm behind the main frame. In this case, the eyelet strip is bent to the back side of the screen and becomes completely invisible from the outside. This allows you to hide the reinforced edging and tensioning elements, resulting in the screen visually creates the impression of a white object suspended in the air (as if the effect of floating). Also, the resulting space behind the cinema screen can be used to place acoustic systems.
Outer frame with eyelets. The most frequently used constructions for cinema screens. Screen cloths of this type are framed with a black border, a looped band, and are stretched on an external frame. Metal frame, wooden constructions or a cable stretch is used as a frame. The eyelet strip is made of double vinyl and either sewn or welded to the screen cloth. The second option of attachment is more reliable, but such products cost a bit more. The luver rings themselves are also welded into this strip – which further increases the strength of the construction of the cloth.
Fastening of the cloth on the buttons. Screen cloth is reinforced around the perimeter of the special edge, which is already attached to the buttons. The edge itself is made of the same double vinyl cloth and the cloth is attached to the back of the frame. In this case, the viewer sees only the black frame of the screen, and the canvas itself – only its white part. The black color of the frame eliminates the reflection of the light flux and increases the visual contrast of the displayed image.