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Encyclopedia > Fresnel lens
Fresnel Lens displayed in the Musée national de la marine in Paris, France
Fresnel Lens displayed in the Musée national de la marine in Paris, France

A Fresnel lens (pronounced [freɪ'nel]) is a type of lens invented by French physicist Augustin-Jean Fresnel. Originally developed for lighthouses, the design enables the construction of lenses of large aperture and short focal length without the weight and volume of material which would be required in conventional lens design. Compared to earlier lenses, the Fresnel lens is much thinner, thus passing more light and allowing lighthouses to be visible over much longer distances. Fresnel A Fresnel lantern (or merely Fresnel) is a spotlight used in theatre, which employs a Fresnel lens to wash light over an area of the stage. ... Image File history File links Download high resolution version (1920x2560, 754 KB) Photograph by Rama File links The following pages link to this file: Fresnel lens ... Image File history File links Download high resolution version (1920x2560, 754 KB) Photograph by Rama File links The following pages link to this file: Fresnel lens ... This article is about the optical device. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... Augustin Fresnel Augustin-Jean Fresnel (pronounced [] in AmE (or fray-NELL), [] in French) (May 10, 1788 – July 14, 1827), was a French physicist who contributed significantly to the establishment of the theory of wave optics. ... Eddystone Lighthouse, one of the first wavewashed lighthouses For other uses, see Lighthouse (disambiguation). ... This article is about focal length related to lenses and systems of lenses. ... This article is about the optical device. ... Eddystone Lighthouse, one of the first wavewashed lighthouses For other uses, see Lighthouse (disambiguation). ...

Contents

Development

The idea of creating a thinner, lighter lens by making it with separate sections mounted in a frame is often attributed to Georges-Louis Leclerc, Comte de Buffon.[1] However, it is difficult to find any other sources that link Buffon to work with optics. French physicist and engineer Augustin-Jean Fresnel is most often given credit for the development of this lens for use in lighthouses. According to Smithsonian, the first Fresnel lens was used in 1822 in a lighthouse on the Gironde River in France, Cardovan Tower; its light could be seen from more than 20 miles out.[2] Scottish physicist Sir David Brewster is credited with convincing the British to use these lenses in their lighthouses.[3][4] Georges-Louis Leclerc, Comte de Buffon, by François-Hubert Drouais (1727-1775). ... Augustin Fresnel Augustin-Jean Fresnel (pronounced [] in AmE (or fray-NELL), [] in French) (May 10, 1788 – July 14, 1827), was a French physicist who contributed significantly to the establishment of the theory of wave optics. ... Smithsonian is a monthly magazine published by the Smithsonian Institution of the United States in Washington, DC External link Smithsonian webpage Categories: Smithsonian Institution | United States magazines | Stub ... 1822 (MDCCCXXII) was a common year starting on Tuesday (see link for calendar) of the Gregorian calendar (or a common year starting on Thursday of the 12-day-slower Julian calendar). ... The Gironde is a navigable estuary, but often referred to as a river, in southwest France. ... Cordouan is a lighthouse located 7 km at sea, geographically located near the mouth of the Gironde estuary in France. ... Sir David Brewster. ...


Detailed information

The Fresnel lens reduces the amount of material required compared to a conventional spherical lens by breaking the lens into a set of concentric annular sections known as Fresnel zones.

In the first (and largest) variations of the lens, each of these zones was a different prism. Though a lens might look like a single piece of glass, closer examination reveals that it is many small pieces. It was not until modern computer-controlled milling equipment (CNC) could turn out large complex pieces that these lenses were single pieces of glass. Image File history File links BIFresnel. ... A CNC Turning Center A CNC Milling Machine The abbreviation CNC stands for computer numerical control, and refers specifically to a computer controller that reads G-code instructions and drives the machine tool, a powered mechanical device typically used to fabricate metal components by the selective removal of metal. ...


For each of these zones, the overall thickness of the lens is decreased, effectively chopping the continuous surface of a standard lens into a set of surfaces of the same curvature, with discontinuities between them. This allows a substantial reduction in thickness (and thus weight and volume of material) of the lens, at the expense of reducing the imaging quality of the lens.


Graphic examples

1: Cross section of a Fresnel lens2: Cross section of a conventional plano-convex lens of equivalent power
1: Cross section of a Fresnel lens
2: Cross section of a conventional plano-convex lens of equivalent power
Close-up of a lighthouse lens

Image File history File links Fresnel_lens. ... Image File history File links Fresnel_lens. ... This article is about the optical device. ... Download high resolution version (1136x793, 200 KB)Lighthouse lens stored at ground-level at Cape Willoughby, Kangaroo Island, South Australia. ... Download high resolution version (1136x793, 200 KB)Lighthouse lens stored at ground-level at Cape Willoughby, Kangaroo Island, South Australia. ...

Uses

Cape Meares Lighthouse (Oregon, USA) first-order Fresnel lens

For the reasons given above, Fresnel lenses tend to be used in applications where imaging quality is not critical, or where the bulk of a solid lens would be prohibitive. Cheap Fresnel lenses can be stamped or moulded out of transparent plastic and are used in overhead projectors, projection televisions, and hand-held sheet magnifying glasses. Fresnel lenses have been used to increase the visual size of CRT displays in pocket televisions, notably the Sinclair TV80. Fresnel lenses are also used in traffic lights and solar forges. Cape Meares Lighthouse Lens, Oregon Taken by Elf | Talk 1996 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Cape Meares Lighthouse Lens, Oregon Taken by Elf | Talk 1996 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Categories: Buildings and structures stubs | Oregon Coast | Lighthouses ... An overhead projector is a display system that is used to display images to an audience. ... A magnifying glass is a single convex lens which is used to see girls better it is wonderful i love eating it is so tasty a mg is used also toproduce a magnified image of an object. ... CRT can mean: Cathode Ray Tube, in electronics, a display device (such as those used in one type of television) C Run-Time, in computing Charitable Remainder Trust, in Law Chinese Remainder Theorem, in mathematics Corneal Refractive Therapy, in medicine Criterion-referenced test, in U.S. schools Critical race theory... Sinclair Research Ltd is a consumer electronics company founded by Sir Clive Sinclair in Cambridge, England (originally as Sinclair Radionics in 1961) to sell hi-fi equipment, calculators, radios and other products. ... The Sinclair TV80, also known as the Flat Screen Pocket TV or FTV1, was a pocket television launched by Sinclair Research in 1984. ... “Traffic Signal” redirects here. ... A solar forge is a device that uses the power of the sun to melt materials, such as asphalt. ...


Fresnel lenses can concentrate much more sunlight than normal convex lenses, and melt certain materials and instantly ignite others. Commercial Fresnel lenses are often available from scientific supply stores and are made of bendable plastic. They can be employed in homemade solar cookers and solar collectors to heat water for domestic use. The CooKit solar panel cooker in use in Africa A solar cooker is a way of using the suns power to cook. ...


Perhaps the most widespread use of Fresnel lenses was in automobile headlamps, where they allow the roughly-parallel beam from the parabolic reflector to be shaped to meet requirements for dipped and main beam patterns, often both in the same headlamp unit (such as the European H4 design). For reasons of cost, weight and impact resistance, newer cars have dispensed with glass Fresnel lenses, using multi-faceted reflectors with plain polycarbonate lenses. However, Fresnel lenses continue to be widely used in automobile tail, marker and backup lights. “Car” and “Cars” redirect here. ... This article does not cite any references or sources. ... H4 or H-4 can mean: For the 18th century chronometer, see John Harrison. ... Polycarbonates are a particular group of thermoplastic polyesters. ...


High-quality glass Fresnel lenses were used in lighthouses; most are now retired from service. Lighthouse Fresnel lens systems typically include extra annular prismatic elements, arrayed in faceted domes above and below the central planar Fresnel, in order to catch all light emitted from the light source. The light path through these elements can include an internal reflection, rather than the simple refraction in the planar Fresnel element. If a shaft of light entering a prism is sufficiently narrow, a spectrum results. ...


Glass Fresnel lenses also are used in lighting instruments for theater and motion pictures (see Fresnel lantern); such instruments are often called simply Fresnels. The entire instrument consists of a metal housing, reflector, lamp assembly, and Fresnel lens. A holder in front of the lens can hold a colored plastic film (gel) to tint the light or wire screens or frosted plastic to diffuse it. Many Fresnel instruments allow the lamp to be moved relative to the lens focal point, to soften or harden the edge of the light beam. The Fresnel lens is useful in the making of motion pictures not only because of its ability to focus the beam brighter than a typical lens, but also because the light is a relatively consistent intensity across the entire width of the beam of light. For other usages see Theatre (disambiguation) Theater (American English) or Theatre (British English and widespread usage among theatre professionals in the US) is that branch of the performing arts concerned with acting out stories in front of an audience using combinations of speech, gesture, music, dance, sound and spectacle &#8212... For other uses see film (disambiguation) Film refers to the celluliod media on which movies are printed Film — also called movies, the cinema, the silver screen, moving pictures, photoplays, picture shows, flicks, or motion pictures, — is a field that encompasses motion pictures as an art form or as... Fresnel A Fresnel lantern (or merely Fresnel) is a spotlight used in theatre, which employs a Fresnel lens to wash light over an area of the stage. ... Child – 5:16 All I Need – 3:55 Drifting – 6:43 Hold On – 4:40 Open Me – 3:35 Beautiful – 5:44 Look In – 4:14 Without You – 4:55 Live It – 7:23 Dont Walk Away – 3:04 Lead Me On – 5:34 Rest – 5:06 Child [Piano...


Aircraft carriers typically use Fresnel lenses in their optical landing system. The "meatball" light aids the pilot in lining up for the landing. In the center are amber and red lights composed of Fresnel lenses. Although the lights are always on, the angle of the lens from the pilot's point of view determines the color and position of the visible light. If the lights appear above the green horizontal bar, the pilot is too high. If it is below, the pilot is too low, and if the lights are red, the pilot is very low. Two aircraft carriers, USS (left), and HMS Illustrious (right), showing the difference in size between a supercarrier and a light V/STOL aircraft carrier. ...


Fresnel reflectors are also currently being incorporated into next-generation solar thermal energy systems. See solar power for more information. The Polaroid SX-70 camera used a Fresnel reflector as part of its viewing system. Solar power describes a number of methods of harnessing energy from the light of the sun. ... SX-70 with electronic flash attachment SX-70 folded up. ...


Multi-focal Fresnel lens are also used as a part of retina identification camera, where they provide multiple in- and out-of-focus images of a fixation target inside the camera. For virtually all users, at least one of the images will be in focus, thus allowing correct eye alignment.


Fresnel lenses have also been used in the field of popular entertainment. The British rock artist Peter Gabriel made use of them in his early solo live performances to magnify the size of his head, in contrast to the rest of his body, for dramatic and comic effect. In the Terry Gilliam film Brazil, plastic Fresnel screens appear ostensibly as magnifiers for the small CRT monitors used throughout the offices of the Ministry of Information. However, they occasionally appear between the actors and the camera, distorting the scale and composition of the scene to humorous effect. Peter Brian Gabriel (born 13 February 1950, in Chobham,[1] Surrey, England) is an English musician. ... Terrence Vance Gilliam (born November 22, 1940) is an American-born British filmmaker, animator, and member of the Monty Python comedy troupe. ...

Lens of Loschen-lighthouse, Bremerhaven
Lens of Loschen-lighthouse, Bremerhaven
Lens of a lighthouse in Rozewie, Poland

Image File history File linksMetadata Download high-resolution version (1659x2535, 423 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Fresnel lens Metadata This file contains additional information, probably added from the digital camera or scanner used to... Image File history File linksMetadata Download high-resolution version (1659x2535, 423 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Fresnel lens Metadata This file contains additional information, probably added from the digital camera or scanner used to... Bremerhaven is a city in the federal state of Bremen, Germany. ... File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Eddystone Lighthouse, one of the first wavewashed lighthouses For other uses, see Lighthouse (disambiguation). ... Rozewie cape as seen from beach in Chłapowo Lighthouse in Rozewie Rozewie is a headland (cape) in Poland. ...

Sizes of lighthouse lenses

Fresnel's lighthouse lenses fell into six orders based on their focal length. The largest (first order) lens has a focal length of 920 mm (36 in), and an optical area 2590 mm (8.5 ft) high. The complete assembly is about 3.7 m (12 ft) tall and 1.8 m (6 ft) wide. The smallest (sixth order) has a focal length of 150 mm (5.9 in) and an optical area 433 mm (17 in) high.[5][6]


Subsequent development extended this to seventh and eighth orders, an intermediate three-and-one-half order, and two orders even larger than first: mesoradial and hyperradial.


Projection uses

Fresnel lenses of different focal lengths (one collimator, and one collector) are used in commercial and DIY projection. The collimator lens has the lower focal length, and is placed closer to the light source, and the collector lens, which focuses the light into the triplet lens, is placed after the projection image (an active matrix LCD panel in LCD projectors). See also: DIY Network, a cable TV network. ... An active matrix liquid crystal display (AMLCD) is a type of flat panel display, currently the overwhelming choice of notebook computer manufacturers, due to light weight, very good image quality, wide color gamut, and response time. ... An LCD projector is a device utilized for displaying video images or data. ...


Generating solar power

Fresnel reflectors are used in Concentrated Solar Power (CSP) plants to produce energy from the sun. Solar thermal energy refers to the idea of harnessing solar power for practical applications from solar heating to electrical power generation. ...


References

  1. ^ "Fresnel lens." Encyclopædia Britannica. 2005. Encyclopædia Britannica Online. 11 November 2005 <http://search.eb.com/eb/article-9035385>.
  2. ^ Watson, Bruce. “Science Makes a Better Lighthouse Lens.” Smithsonian. August 1999 v30 i5 p30. produced in Biography Resource Center. Farmington Hills, Mich.: Thomson Gale. 2005. <http://libproxy.uncg.edu:2088/servlet/BioRC>.
  3. ^ "Brewster, Sir David." Encyclopædia Britannica. 2005. Encyclopædia Britannica Online. 11 November 2005 <http://search.eb.com/eb/article-9016395>.
  4. ^ "David Brewster." World of Invention, 2nd ed. Gale Group, 1999. Reproduced in Biography Resource Center. Farmington Hills, Mich.: Thomson Gale. 2005. <http://libproxy.uncg.edu:2088/servlet/BioRC>.
  5. ^ Mabel A. Baiges (1988). Fresnel Orders (TIFF). Retrieved on 2007-06-01.
  6. ^ Fresnel lenses. Retrieved on 2007-06-01. Note the transcription error in the "Comparative Table of Lens Orders; the "oil consumption per hour" columns should be titled grams and ounces, not gallons.

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External links


  Results from FactBites:
 
The Fresnel Lens - LongIslandLighthouses.com (1247 words)
Fresnel was the first person to demonstrate that two beams of light polarized in different planes do not exhibit interference effects and, from this experiment, theorized that light waves are transverse, rather than longitudinal (like that of sound).
Fresnel's scientific work was known only to a small group of scientists during his lifetime, and some of his papers were not published until after his death.
The single, nonrevolving lens, which is the same type of lens one sees on many 19th century hand-held lanterns, sends a steady beam in all directions unless the lamp inside employs some sort of rotating shutters, either solid or colored glass, which cause a flashing effect to the observer.
  More results at FactBites »

 
 

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