Silver screen
Encyclopedia
A silver screen, also known as a silver lenticular screen, is a type of projection screen
Projection screen
A projection screen is an installation consisting of a surface and a support structure used for displaying a projected image for the view of an audience. Projection screens may be permanently installed, as in a movie theater; painted on the wall; or semi-permanent or mobile, as in a conference room...

 that was popular in the early years of the motion picture industry and passed into popular usage as a metonym for the cinema industry. The term silver screen comes from the actual silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

 (or similarly reflective aluminum) content embedded in the material that made up the screen's highly reflective surface.

Actual metallic screens are coming back into use in projecting 3-D film
3-D film
A 3-D film or S3D film is a motion picture that enhances the illusion of depth perception...

s.

Characteristics

Silver lenticular (vertically ridged) screens, which are made from a tightly woven fabric, either natural, such as silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...

, or a synthetic fiber
Synthetic fiber
Synthetic fibers are the result of extensive research by scientists to improve on naturally occurring animal and plant fibers. In general, synthetic fibers are created by forcing, usually through extrusion, fiber forming materials through holes into the air, forming a thread...

, were excellent for use with low-power projector
Movie projector
A movie projector is an opto-mechanical device for displaying moving pictures by projecting them on a projection screen. Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras.-Physiology:...

 lamp heads and the monochromatic images that were a staple of early projected images. Other silver screens are made by taking normal matte
Matte
Matte may refer to:In film:* Matte , filmmaking and video production technology* Matte painting, a process of creating sets used in film and video* Matte box, a camera accessory for controlling lens glare...

 sheets and adhering silver dust to them; the effect is the same.

True silver screens, however, provide narrower horizontal/vertical viewing angle
Viewing angle
In display technology parlance, viewing angle is the maximum angle at which a display can be viewed with acceptable visual performance. In a technical context, this angular range is called viewing cone defined by a multitude of viewing directions....

s compared to their more modern counterparts because of their inability to completely disperse light. In addition, a single projection source tends to over-saturate the center of the screen and leave the peripheries darker, depending on the position of the viewer and how well adjusted the lamp head is, a phenomenon known as hot-spotting. Due to these limitations and the continued innovation of screen materials, the use of silver screens in the general motion picture exhibition industry has mostly been phased out.

Use in 3-D projection

Silver lenticular screens, while no longer employed as the standard for motion picture projection, have come back into use as they are ideally suited for modern 3-D film
3-D film
A 3-D film or S3D film is a motion picture that enhances the illusion of depth perception...

 polarized projection. The percentage of light reflected from a non-metallic (dielectric) surface varies strongly with the direction of polarisation and the angle of incidence; this is not the case for an electric conductor such as a metal (as an illustration of this, sunlight reflected from a horizontal surface such as a reflective road surface or water is attenuated by polarized sunglasses
Sunglasses
Sunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that...

 relative to direct light; this is not the case if the light is reflected from a metallic surface). As many 3-D technologies in use today depend upon maintaining the polarisation of the images to be presented to each eye, the reflecting surface needs to be metallic rather than dielectric.

Additionally, the nature of polarized 3-D projection requires the use of interposed filters, and the overall image is consequently less bright than if it were being normally projected. Silver lenticular screens help compensate by reflecting more light back than a "modern" screen would—the same purpose they originally served in the early days of motion pictures.

Other screen types

Each of these screen types continues to enjoy widespread popularity for both home and business applications:
  • Aluminized screen
    Aluminized screen
    Aluminized screen is a cathode-ray tube screen whose brightness is increased by coating the phosphor with a thin layer of aluminium. Light from an excited part of the phosphor that would normally shine back inside the tube is thus reflected forward, increasing the total light output from the screen...

Similar to a silver screen, but using aluminum to coat the surface. Used for 3D films for the same reason as silver screens.
  • Pearlescent screen
Similar to a silver screen, this screen has narrow viewing angles and a higher gain (the measure of reflected light), but it does suffer from color-shifts to red and a tendency to hot spot.
  • Glass-beaded screen
This screen type also has a higher gain; however, the nature of its construction results in limited viewing angles and a loss of resolution since glass-beaded screens are retro-reflective, that is, their reflection is directed back toward the light source. The glass-beaded surface can develop noticeable dark spots with age or mishandling as the beads can wear off. Popular in the amateur market.
  • Gray screen
Also known as a high contrast screen, because its purpose is to boost contrast on projectors in viewing rooms that are not entirely dark, as the gray screen absorbs ambient light that strikes it better than a white screen does. Essentially, the screen only reflects the specific shades of red, green, and blue output by a trichromatic video projector
Video projector
A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other...

, and absorbs the remainder. Therefore the projected image is reflected normally, but other light is not. In so doing the black level on the screen is maintained. Mostly used with digital projectors in non-commercial settings.
  • Matte white screen
    Diffuse reflection
    Diffuse reflection is the reflection of light from a surface such that an incident ray is reflected at many angles rather than at just one angle as in the case of specular reflection...

This screen provides the widest viewing angles while producing no glare and no hot spotting. These characteristics have made it the most common variety of screen currently produced and has allowed it to become the entertainment industry's standard.
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