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Projector Screen Geometry Throw Ratio
A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen. Most projectors create an image by shining a light through a small transparent lens, but some newer types of projectors can project the image directly, by using lasers. A virtual retinal display, or retinal projector, is a projector that projects an image directly on the retina instead of using an external projection screen. The most common type of projector used today is called a video projector. Video projectors are digital replacements for earlier types of projectors such as slide projectors and overhead projectors. These earlier types of projectors were mostly replaced with digital video projectors throughout the 1990s and early 2000s, but old analog projectors are still used at some places. The newest types of projectors are handheld projectors that use lasers or LEDs to project images. Movie theaters used a type of projector called a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IFA 2012 IMG 5767
IFA or Ifa may refer to: Organisations Economics * Independent financial adviser, a type of financial services professional in the UK * Index Fund Advisors * Institute and Faculty of Actuaries, representing actuaries in the UK * Institute of Actuaries, in England, Wales and Northern Ireland * Faculty of Actuaries, in Scotland * Institute of Financial Accountants, representing accountants in the UK * International Fiscal Association * International Forfaiting Association Sports * Intercollegiate Fencing Association * International Fistball Association ;Football * Indian Football Association, West Bengal, India * Indoor Football Alliance * Intercollegiate Football Association, college football organization, 1873–1893 * Iraq Football Association * Irish Football Association, in Northern Ireland * Islamabad Football Association * Israel Football Association Other organizations * Illinois Family Action, the lobbying arm of the Illinois Family Institute in the US * India Foundation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magic Lantern
The magic lantern, also known by its Latin name , is an early type of image projector that uses pictures—paintings, prints, or photographs—on transparent plates (usually made of glass), one or more lens (optics), lenses, and a light source. Because a single lens inverts an image projected through it (as in the phenomenon which inverts the image of a camera obscura), slides are inserted upside down in the magic lantern, rendering the projected image correctly oriented. It was mostly developed in the 17th century and commonly used for entertainment purposes. It was increasingly used for education during the 19th century. Since the late 19th century, smaller versions were also mass-produced as toys. The magic lantern was in wide use from the 18th century until the mid-20th century when it was superseded by a compact version that could hold many 35 mm photographic slides: the slide projector. Technology Apparatus The magic lantern used a concave mirror behind a light so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Movie Projector
A movie projector (or film projector) is an optics, opto-mechanics, mechanical device for displaying Film, motion picture film by projecting it onto a movie screen, screen. Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras. Modern movie projectors are specially built video projectors (see also digital cinema). Many projectors are specific to a particular film gauge and not all movie projectors are film projectors since the use of film is required. Predecessors The main precursor to the movie projector was the magic lantern. In its most common setup it had a concave mirror behind a light source to help direct as much light as possible through a painted glass picture slide and a lens, out of the lantern onto a screen. Simple mechanics to have the painted images moving were probably implemented since Christiaan Huygens introduced the apparatus around 1659. Initially, candles and oil lamps were used, but oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enlarger
An enlarger is a specialized transparency Image projector, projector used to produce Photography, photographic prints from film or glass Negative (photography), negatives, or from reversal film, transparencies. Construction All enlargers consist of a light source, normally an incandescent light bulb shining though a condenser (optics), condenser or translucent screen to provide even illumination, a holder for the negative or transparency, and a specialized lens for projection, though some, such as the Rapid Rectilinear or Aplanat could be used in both camera and enlarger. Enlarger lenses, like the Dialyte lens, dialyte construction, are generally symmetrical in design or nearly so, optimised for sharp focus at 2x to 10x magnification. The light passes through a Photographic film, film holder, which holds the exposed and Film developing, developed photographic negative or transparency. Prints made with an enlarger are called ''enlargements''. Typically, enlargers are used in a dar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Magic Mirrors
The Chinese magic mirror () traces back to at least the 5th century, although their existence during the Han dynasty (206 BC – 24 AD) has been claimed. The mirrors were made out of solid bronze. The front was polished and could be used as a mirror, while the back has a design cast in the bronze, or other decoration. When sunlight or other bright light shines onto the mirror, the mirror appears to become transparency and translucency, transparent. If that light is reflected from the mirror onto a wall, the pattern on the back of the mirror is then projected onto the wall. Bronze mirrors were the standard in many Eurasian cultures, but most lacked this characteristic, as did most Chinese bronze mirrors. Construction Robert Temple describes their construction: The basic mirror shape, with the design on the back, was cast flat, and the convexity of the surface produced afterwards by elaborate scraping and scratching. The surface was then polished to become shiny. The stress ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magic Lantern
The magic lantern, also known by its Latin name , is an early type of image projector that uses pictures—paintings, prints, or photographs—on transparent plates (usually made of glass), one or more lens (optics), lenses, and a light source. Because a single lens inverts an image projected through it (as in the phenomenon which inverts the image of a camera obscura), slides are inserted upside down in the magic lantern, rendering the projected image correctly oriented. It was mostly developed in the 17th century and commonly used for entertainment purposes. It was increasingly used for education during the 19th century. Since the late 19th century, smaller versions were also mass-produced as toys. The magic lantern was in wide use from the 18th century until the mid-20th century when it was superseded by a compact version that could hold many 35 mm photographic slides: the slide projector. Technology Apparatus The magic lantern used a concave mirror behind a light so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large-format Slide Projector
A large-format slide projector (also often called large-format projector or large-image projector) is a kind of slide projector for large image projection which has a very powerful light source (up to 12 thousand watts using arc lamps). The light source generates a lot of heat even when filtered to only visible light; the projected transparency is protected from overheating by the heat being distributed across its large area, and cooling fans. Slide formats include 18 × 18 cm (7.1 × 7.1") or 24 × 24 cm (9.4 × 9.4"). Projection art These formats are so large that it is possible to project slides painted with heat resistant translucent colours as a special kind of art (projection art). The light output of the projector is large enough to project onto whole buildings. History The first large-format slide projectors were built in the middle of the 20th century as background projectors for theaters and opera houses. From the early 50', the german Brand Reiche&Vogel w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slide Projector
A slide projector is an optical device for projecting enlarged images of photographic slides onto a screen. Many projectors have mechanical arrangements to show a series of slides loaded into a special tray sequentially. 35 mm slide projectors, direct descendants of the larger-format magic lantern, first came into widespread use during the 1950s for slide shows as home entertainment, and for use by educational and other institutes. Reversal film created a small positive projectable image rather than the negatives used since the early days of photography; photography now produced 35mm directly viewable small colour slides, rather than large monochrome negatives. The slide images were too small for unaided viewing, and required enlargement by a projector or enlarging viewer. Photographic film slides and projectors have been replaced by image files on digital storage media shown on a projection screen by using a video projector, or displayed on a large-screen video ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shadow Projector
A shadow is a dark area on a surface where light from a light source is blocked by an object. In contrast, shade (shadow), shade occupies the three-dimensional volume behind an object with light in front of it. The cross section (geometry), cross-section of a shadow is a two-dimensional silhouette, or a reverse Projection (linear algebra), projection of the object blocking the light. Point and non-point light sources A point source of light casts only a simple shadow, called an "umbra". For a non-point or "extended" source of light, the shadow is divided into the Umbra, penumbra and antumbra, umbra, penumbra, and antumbra. The wider the light source, the more blurred the shadow becomes. If two penumbras overlap, the shadows appear to attract and merge. This is known as the shadow blister effect. The outlines of the shadow zones can be found by tracing the rays of light emitted by the outermost regions of the extended light source. The umbra region does not receive any direct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
