File 20100105 MultifocalGlass.jpg thumb right View through a progressivelens at some distance. In nor ... Progressive powered lenses the Minkwitz theorem Sheedy JE, Campbell C, Optom Vis Sci. 2005 Oct 82 10 916 22 ref Aves patent included the progressivelens design and the manufacturing process. However ... Today the complex surfaces of a progressivelens can be cut and polished on computer controlled ... age , proponents have suggested the lack of segments on the lens surface of a progressivelens ... a progressivelens design, an eyecare practitioner will usually ask some lifestyle questions, which ... for various models of progressivelens. Different lenses have different glazing restrictions ... lenses Sheedy JE Optom Vis Sci. 2004 May 81 5 350 61 DEFAULTSORT ProgressiveLens Category Corrective .... Progressive spectacle lenses , also called progressive addition lenses PAL , progressive power lenses , graduated prescription lenses , and varifocal or multifocal lenses , are corrective lens es ... . They are characterised by a gradient of increasing optical power lens power , added to the wearer ... prescription, at the top of the lens optics lens and reaches a maximum addition power, or the full reading addition, at the bottom of the lens. The length of the progressive power gradient on the lens surface depends on the refractive index of the lens, with a final addition power between 0.75 to 3.50 ... several intermediate steps H. Newbold appears to have designed a similar lens to Aves around 1913 , there is evidence ref Bennett A. 1973 Variable and Progressive power lenses. Manufacturing ... surfaces. The Varilux lens was the first PAL of modern design. It was developed by Bernard Maitenaz ... of Essilor in 1959. Early progressive lenses were relatively crude designs but modern sophisticated progressive lenses have gained greater patient acceptance and include special designs to cater to many separate types of wearer application for example progressive addition lenses may be designed with distance ... more details
wiktionarypar lensLens or Lense may refer to TOC right Optics Lens optics , an optical element which converges or diverges light Lens anatomy , a part of the eye Corrective lens for correction of human vision Contact lens , placed on the cornea of the eye Photographic lens , a lens designed for use on a camera Focusing of other radiation and forces Gravitational lens , a massive astronomical object which causes visual distortions Electrostatic lens , a device used to focus or collimate electron beams Explosive lens , a shaped explosive charge with focused blast Microwave lens , used to focus microwave radiation in slotted waveguide antennas Lentil shaped things Lens genus , the genus of the lentil plant Lens geometry , a geometric shape formed from two arcs Lens geology , a body of ore or rock that is thick in the middle and thin at the edges Lens hydrology , a layer of fresh water derived from rainfall, overlying saline groundwater Kamera lens biology , a unicellular, flagellate organism and the only species of the genus Kamera. Places Arrondissement of Lens , in the d partement of Pas de Calais, France Lens, Pas de Calais , a commune in that arrondissement RC Lens , its football soccer club Lens, Belgium Lens, Valais , Switzerland People Louis Lens , Flemish rose breeder Nicholas Lens , Belgian composer Josef Lense , physicist Jeremain Lens , Dutch Surinam footballer Other uses Laser engineered net shaping , a rapid prototyping technology capable of building fully dense metal parts Perspective cognitive Lens, a fictional alien device in E. E. Smith s Lensman series disambig surname an Lens de Lens es Lens eo Lens fr Lens it Lens nl Lens pms Lens pt Lens sco Lens simple Lens disambiguation sk Lens sv Lens tr Lens vo Lens ... more details
Infobox single See Wikipedia WikiProject Songs Name Into the Lens Cover Into the Lens.jpg Artist Yes band Yes Album Drama Yes album Drama B side Does It Really Happen? Released 1980 Format 7 Recorded Genre Progressive rock Length 3 47 Label Atlantic Records Atlantic Writer Geoff Downes , Trevor Horn , Steve Howe guitarist Steve Howe , Chris Squire , Alan White Yes drummer Alan White Producer Yes and Eddie Offord Chronology Last single Don t Kill The Whale br 1978 This single Into the Lens br 1980 Next single Owner of a Lonely Heart br 1983 Infobox single Name I Am a Camera Type Single Artist The Buggles from Album Adventures in Modern Recording Cover I Am A Camera Single Cover.jpg B side Fade Away Released October 1981 Format 7 , 12 Genre Synthpop Length 4 32 Label Carrere Records Carrere Writer Geoff Downes , Trevor Horn Producer Trevor Horn Last single Elstree song Elstree br 1980 This single I Am a Camera br 1981 Next single Adventures in Modern Recording song Adventures in Modern Recording br 1982 Into the Lens is a song originally written by Trevor Horn and Geoff Downes of The Buggles . It was first released as Into the Lens on the Yes band Yes album Drama Yes album Drama in 1980, and the year after on Adventures in Modern Recording , the second and last album of The Buggles. Both versions were also released as singles Into the Lens I Am a Camera by Yes in 1980 and I Am a Camera ... Howe guitarist Steve Howe , Chris Squire and Alan White Yes drummer Alan White , and therefore, Into the Lens features a more distinctive progressive Rock prog rock sound. When Horn and Downes resumed ... I Am a Camera was a Buggles track and we had adapted it into a Yes track. It became Into the Lens and, naturally, slightly more overblown. I don t mind Into the Lens the melody s unadulterated while ... different lyrics, notably I will never let you go, and you always let the feelings show Into the Lens ... edit of Yes own Into the Lens was entitled Into the Lens I Am a Camera . The line I am a camera is a quote ... more details
Progressive jackpot , a jackpot where the value increases for every game played Progressivelens ...wiktionary Progressive progressively progressiveness unprogressive unprogressively Progressive is an adjectival ... , a political ideology Progressive Era , a period of reform in the United States ca. 1890 1930 Progressive Party disambiguation , any of several political parties Progressive tax , a type of tax rate structure The Progressive , a left wing magazine Progressive realism , an American foreign policy paradigm ... Progressive Caucus , members within the Democratic Party in the United States Congress dedicated to the advancment of progressive issues and positions Business Progressive Corporation , a US insurance company Progressive Enterprises , a New Zealand retail cooperative Music Progressive music disambiguation , an approach to musical composition Progressive rock , a subgenre of rock music Progressive metal , a genre of heavy metal music Progressive country , a subgenre of country music Progressive electronic music , a collection of electronic dance music genres Progressive folk music , originally a type of American folk music that pursued a progressive political agenda, in the UK the term became attached to a sub genre that encourages stylistic or thematic innovation Progressive Hip Hop , hip ... Progressive psytrance , a style of trance music Progressive post hardcore , derived from hardcore punk which had typically featured very fast tempos, loud volume and heavy bass levels Progressive rock radio format , a radio station programming format Progressive album Progressive album , a demo by the band Haggard band Haggard Progressive song Progressive song , Kalafina s sixth single Religion Progressive Adventism , members of the Seventh day Adventist Church who disagree with certain beliefs traditionally held by mainstream Adventism and officially by the church Progressive Christianity , a movement within contemporary Protestantism Progressive creationism , a form of Old Earth creationism ... more details
Citations missing date November 2007 distinguish2 the Progressive Building Society trading name The Progressive Infobox Magazine title The Progressive image file Progressive Cover 10 02.jpg image size 200px image caption October 2002 cover editor Matthew Rothschild editor title Editor previous editor staff writer frequency Monthly circulation category Politics , culture company The Progressive Magazine publisher firstdate 1909 country USA based Madison, Wisconsin language English website http www.progressive.org www.progressive.org issn 0033 0736 The Progressive is an American monthly magazine of politics, culture and progressivism with a pronounced Modern liberalism in the United States liberal ... from August 1945 to the present. History Advert date April 2011 The Progressive was founded on January ... La Follette s Weekly , its name was changed to The Progressive in 1929. ref cite news last Thelen ... accessdate 2008 07 09 ref The campaigns The Progressive has led include the fight to stay out ... Earth Day issue in 1970 entitled The Crisis of Survival . In 1979 Anchor nuclear secrets , The Progressive ... to the United States Constitution First Amendment case of prior restraint , United States v. The Progressive .... During the 1990s, The Progressive campaigned on behalf of Immigration to the United States immigrants .... WXXM FM in Madison, Wisconsin , an Air America Radio affiliate, features a Progressive Radio show ... across the country, as is a daily audio editorial, The Progressive Point of View , which features ... Left s Circulation and Magazine s ref Contributors Throughout the years, The Progressive has published ... Kucinich and Bernie Sanders . ref cite news title The Progressive Magazine to Celebrate Its 90th Anniversary ... . The editor of The Progressive is Matthew Rothschild. Its editorial offices are in Madison, Wisconsin ... EnglishCurrentAffairs DEFAULTSORT Progressive Category Alternative magazines Category American political ... established in 1909 Category Magazines published in Wisconsin ar de The Progressive ... more details
about varifocal camera lenses corrective eyeglass lenses Progressivelens A varifocal lens is a camera lens with variable focal length in which Focus optics focus changes as focal length and magnification changes, as compared to parfocal lens parfocal true zoom lens , which remains in focus as the lens zooms focal length and magnification change . Many so called zoom lenses, particularly in the case of fixed lens cameras, are actually varifocal lenses . ref cite web url http www.rogercavanagh.com helpinfo 30 parfocal.stm title Parfocal Lenses accessdate 2007 11 18 last Cavanagh first Roger date 2003 05 29 archiveurl http web.archive.org web 20071007070643 http www.rogercavanagh.com helpinfo 30 parfocal.stm Bot retrieved archive archivedate 2007 10 07 ref Image Varifocal example.jpg thumb 500px none A varifocal lens. Left image is at 2.8mm, in focus. Middle image is at 12mm with the focus left alone from 2.8mm. Right image is at 12mm refocused. The close knob is focal length and the far knob is focus. References Footnotes reflist Notations cite web url http www.tokina usa.com glossary.html title Lens Glossary accessdate 2007 11 18 work Tokina Industrial, Inc. optics stub Category Photographic lenses es Varifocal ja pt Lente varifocal ... more details
or concave. Convex aspheric curvatures are used in many presbyopia presbyopic Progressivelens vari ... for myopes do not necessarily need progressive add portions, because the design of the lens curvature ... of high minus lenses are ground onto the posterior side of the lens. Progressive add reading portions ...Image Pfeilh he.svg thumb right upright An aspheric biconvex lens. An aspheric lens or asphere is a lens optics lens whose surface profiles are not portions of a sphere or Cylinder geometry cylinder . In photography , a lens assembly that includes an aspheric element is often called an aspherical lens ... reduce other Aberration in optical systems optical aberrations compared to a simple lens . A single aspheric lens can often replace a much more complex multi lens system. The resulting device is smaller and lighter, and possibly cheaper than the multi lens design. Aspheric elements are used in the design of multi element wide angle lens wide angle and fast normal lens es to reduce aberrations. They are also ... lenses are also sometimes used for eyeglasses . These are typically designed to give a thinner lens .... ref name opticampus Cite web url http www.opticampus.com cecourse.php?url lens design &OPTICAMP f1e4252df70c63961503c46d0c8d8b60 asphericity title Ophthalmic Lens Design first Darryl last Meister ... best form lenses, but rather allow a thinner, flatter lens to be made without compromising the optical ... aspheric lens Small glass or plastic aspheric lenses can be made by molding, which allows cheap ... is by depositing optical resin onto a spherical lens to form a composite lens of aspherical shape ... on a spindle below the lens, and mounting tool on a second spindle swung out uses Pitch resin pitch to hold the lens shown with its concave side down The non spherical curvature of an aspheric lens can ..., as the CR 39 resin lens is. Techniques such as laser ablation can also be used to modify the curvature of a lens, but the polish quality of the resulting surfaces is not as good as those achieved ... more details
. ProgressiveProgressivelensProgressive or varifocal provide a smooth transition from distance correction ... within a small region of the lens surface. Progressivelens The progressive addition lens PAL, also commonly called a progressivelens eliminates the line in bi tri focals and are very complex in their profile ... in the surrounding space beyond the edges of the lens. Bifocal, trifocal, and progressive ...Image Bifoklabrille fcm.jpg thumb right 200px A bifocal corrective eyeglass lens Image Contactlenzen ... upward A corrective lens is a lens optics lens worn in front of the Human eye eye , mainly used to treat ... on the face a short distance in front of the eye. Contact lens es are worn directly on the surface of the eye. Intraocular lens es are surgically implanted most commonly after cataract removal, but recently ... requires a divergent lens, whereas hyperopia far sightedness requires convergent lens. Prescription ... necessary to make the lens. Prescriptions typically include the power specifications of each lens for each .... For example a lens with sphere, cylinder of 2.25, 1.50 would convert to 3.75, 1.50 . Axis component ... almost always separated by 90 , the axis is also the location of the sphere component. If the lens is spherical ... if the cylinder is positive, the lens is most convergent 90 from the axis if the cylinder is negative, the lens is most divergent 90 from the axis Sample prescription So, a prescription of 1.00 0.25 x 180 describes a lens that has a horizontal power of 1.00 D and a vertical power of 0.75. The same prescription written in minus cylinder notation 0.75 0.25 x 090 Other considerations Lens types Single ... vision see Lens types Lens Types below . Infrequently, prism correction prism and base curve values ... object bigger, the main advantage comes from the power of the lens. Over the counter readers are spherical ... binocularity. They can test to see if over the counter corrective lenses are appropriate. Lens ... of the lens. Single lenses in CR 39 plastic come finished and unfinished. An unfinished lens is ground ... more details
Unreferenced date August 2009 A Celor lens is a highly corrected photographic lenslens of the Dialyt lens Dialyt type, designed for process photography , involving reproduction at or near 1 1 scale. DEFAULTSORT Celor Lens Category Photographic lenses optics stub ... more details
Unreferenced date December 2009 Image Canon EFS 18 to 55 m lense covers.JPG thumb Canon company Canon lens covers. File 62mm lens cap.jpg thumb Screw in metal lens cap A lens cover or lens cap provides protection from scratches and minor collisions for camera and camcorder photographic lens lenses . Lens covers come standard with most cameras and lenses. Some mobile camera phone s include lens covers, such as the Sony Ericsson W800 , the Sony Ericsson K750 and the Sony Ericsson K550 . A more secure lens cap is the metal screw in lens cap which cannot pop off a lens accidentally. Although a screw in cap takes more time to remove in order to take a photograph than a standard lens cap, it is stronger than plastic and therefore more protective. See also Lens hood DEFAULTSORT Lens Cover Category Photography equipment ... more details
Infobox French commune name Lens Lestang region Rh ne Alpes department Dr me arrondissement Valence canton Le Grand Serre INSEE 26162 postal code 26210 mayor Jean Pierre Olmos term 2008&ndash 2014 intercommunality Rh ne Valloire longitude 5.04333333333 latitude 45.2925 elevation m 300 elevation min m 237 elevation max m 448 area km2 16.41 population 801 population date 2008 Lens Lestang is a Communes of France commune in the Dr me Departments of France department in southeastern France . Population D mographie 1911 976 1962 609 1968 655 1975 636 1982 672 1990 629 1999 667 2008 801 See also Communes of the Dr me department References http www.insee.fr en home home page.asp INSEE reflist commonscat Dr me communes DEFAULTSORT Lenslestang Category Communes of Dr me Dr me geo stub ca Lens Lestang ceb Lens Lestang es Lens Lestang eu Lens Lestang fr Lens Lestang it Lens Lestang ms Lens Lestang nl Lens Lestang oc Lens Lestang pms Lens Lestang pl Lens Lestang pt Lens Lestang bug Lens Lestang uk vi Lens Lestang vo Lens Lestang war Lens Lestang ... more details
Bernard Lens may refer to one of three British artists Bernard Lens 1631 1708 , probably from the Netherlands , also the writer of several religious tracts Bernard Lens II 1659 1725 , son of the former, mezzotint engraver Bernard Lens III 1682 1740 , son of the former, portrait miniature portrait miniaturist Category Artist families Lens Category Portrait miniaturists Lens, Bernard Category British engravers Lens, Bernard ... more details
Refimprove date June 2011 File Lens flare scheme en.svg thumb Scheme of lens flare. Lens hood is designed in the way that it does not block the angle of view of the lens. Lens hoods block the sun or other light source in order to prevent glare and lens flare. File Tulip Lens Hood.jpg thumb A conical petal lens hood. In photography , a lens hood or lens shade is a device used on the end of a photographic lenslens to block the sun or other light source in order to prevent glare vision glare and lens flare . ref van Walree, Paul Lens hoods, http toothwalker.org optics lenshood.html ref The geometry of the lens hood can vary from a plain cylindrical or conical section much like a lamp shade to a more ... produce a reasonable good shade without blocking the field of view of the lens and thus producing vignetting . Properly petal shaped lens hoods produce more shade than normal lens hoods with the same end diameter. Square lens hoods may be even better. Lens hoods are more prominent in long focus lens es because the field of view has a smaller Angle of view viewing angle than of wide angle lens es. For wide angle lenses, the length of the hood away from the end of the lens cannot be as long as those for telephoto lenses because of the viewing angle. Lens hoods are often designed to fit onto the matching lens facing either forward, for normal use, or backwards, so that the hood may be stored with the lens without occupying much additional space. Some lens hoods are flexible and collapse for storage. In addition, they offer some physical protection for the lens due to the hood extending farther than the lens itself ref Harmer, Jim, http improvephotography.com 1101 lens hood purpose dslr What does a lens hood do? , Improve Photography , 15 Jun 2011 ref . gallery File Canon EF 70 200mm F2.8L lens with hood.jpg A conical petal lens hood used on the Canon EF 70 200mm lens . Note that from this angle no part of the glass lens surface is visible, as the line of sight is blocked by the lens ... more details
Sidney Lens 1912 1986 , also known by his party name Sid Okun , was an United States American labor leader, political activist, and author, best known for his book, The Day Before Doomsday , which warns of the prospect of nuclear annihilation, published in 1977 by Doubleday publisher Doubleday . He also wrote a history of U.S. intervention abroad, The Forging of the American Empire , originally published in 1974 and republished in 2003 by Haymarket Books with a new introduction by Howard Zinn and an autobiography , Unrepentant Radical . Formerly a member of Hugo Oehler s Revolutionary Workers League Oehlerite Revolutionary Workers League , Lens was active in retail worker unions in Chicago ref Sidney Lens, Unrepetant Radical Boston Beacon Press, 1980 ref and in the anti war movement during the Vietnam War . In 1968, he signed the Writers and Editors War Tax Protest pledge, vowing to refuse tax payments in protest against the Vietnam War. ref Writers and Editors War Tax Protest January 30, 1968 New York Post ref Lens was an editor of The Progressive . In 1980, Lens was the Citizens Party United States candidate for United States Senate in Illinois . List of works http www.archive.org details JohnDeweyAMarxianCritique John Dewey, a Marxian critique Chicago Revolutionary workers league, U.S. 1942 written under the pseudonym Sid Okun Left, Right, and Center Chicago Henry Regnery, 1949 explains some of the anomalies of the American labor movement The Counterfeit Revolution Boston Beacon Press, 1952 why Stalinism, despite its corrupt nature, nonetheless appeals to millions of people in the non communist world A World in Revolution 1956 revolutionary movements around the word, based on extensive travels The Crisis of American Labor 1959 Working Men 1960 a history of labor, for young ... reflist Persondata Metadata see Wikipedia Persondata . NAME Lens, Sidney ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH 1912 PLACE OF BIRTH DATE OF DEATH 1986 PLACE OF DEATH DEFAULTSORT Lens ... more details
The Gauss lens consists of two lens optics lenses in its most basic form, a positive Lens optics Types of simple lenses meniscus lens on the object side and a negative meniscus lens on the image side. The Optical power power of the positive element predominates, but the negative element corrects for chromatic aberration . See also Double Gauss lens Category Lenses optics stub ... more details
additionalcitations date April 2011 A Lens Controller is device that controls motorized photographic lens functions such as Zoom lens zoom , Focus optics focus , and Iris diaphragm iris or aperture. ref Kruegle, Herman 2007 . CCTV Surveillance , Butterworth Heinemann. ref Lens controllers can be found internally in modern still camera photographic lens es and as a stand alone unit in machine vision , remote sensing , optoelectronics systems, and security applications. Internal Photographic Lens Controllers Internal lens controllers take information from the camera or lens elements and perform automatic ... zoom lens and used mainly for photography. Stand Alone Photographic Lens Controllers Stand alone lens controllers are attached to a photographic lens by a cable to allow operator manual control of lens functions. Machine Vision, CCTV, or Computer Vision Lens Controllers Lens controllers for machine ... there is no standard for wiring of lenses most have Direct Current DC motors attached to lens elements and are controlled with 6 VDC, 8 VDC or 12 VDC. Machine vision lens controllers come in manual or computerized varieties. Manual lens controllers are composed of switches and a power supply. When the operator actuates a switch , a function of the lens is enabled. Manual control requires an operator to view the image through the lens in which adjustment is taking place. Manual lens controllers are the most common and are frequently used in CCTV security systems. Computerized lens controllers ... interface. A remote computer sends a command to the lens controller through an RS232 , RS485 , USB , or Ethernet interface to actuate a lens function. The Lens Controller will then perform the command automatically. If a lens is equipped with presets, potentiometers attached to lens ... and move to a specific position. If the lens is not equipped with presets, then the controller can only move a lens function to an approximate position. References See Wikipedia Footnotes on how to create ... more details
Unreferenced stub auto yes date December 2009 In optics , a simple lens or singlet lens is a lens optics lens consisting of a single simple element. Typical examples include a magnifying glass or a lens in a pair of simple glasses reading glasses . Simple lenses are prone to aberration in optical systems aberrations , especially chromatic aberration . They cannot be used for precise imaging and make poor camera lens es. They are commonly used for laser applications, however, where the beams are both monochromatic minimizing chromatic aberration and narrow minimizing spherical aberration . Some camera s with Focus free lens fixed lenses have been made using a simple lens, usually a meniscus lens with the convex face facing outward. In such examples the lens aperture is made small and in some cases such as the Kodak Brownie camera Brownie 127 camera , the photographic film film plane is curved to reduce the impact of aberrations. See also Lens optics Doublet lens Aspheric lens DEFAULTSORT Simple Lens Category Photographic lenses Category Lenses Optics stub zh ... more details
In imaging optics, a field lens is a positive powered lens or group of lenses that comes after the objective lens and before the image plane or the eyepiece , serving to change the size of the image, ref http www.colorado.edu physics phys1230 phys1230 fa01 topic43.html Judah Levine, University of Colorado Physics 1230 Light and Color The Field Lens. Fall 2001 ref ref http spie.org x34410.xml SPIE Optopedia Field Lens ref or to provide image space telecentricity . Reference references optics stub Category Lenses Category Microscope components de Feldlinse ... more details
Image cambo lens board.jpg thumb right 200px Cambo lens board with Copal 1 A Lens board commonly spelled as lensboard is a photographic part used for securing a lens to the front standard of a large format view camera . The lens board itself is usually flat, square, and made of metal most commonly Aluminum or wood and sometimes plastic. The lens board will have a hole of various diameters drilled dead center on the board. A lens board typically varies between 1 and 4 millimeters in thickness. The overall size and shape of the lens board depends on the brand of camera and film format used. Some cameras will use 2 to 4 screws to secure the lens board to the front standard of the view camera, most commonly however, the lens board will be secured by one or more locking levers or tabs to allow tool less removal of the lens board. The rear surface of a lens board is usually painted matte black to keep light entering the camera through the lens during exposure from reflecting off the surface and interfering with the projected image. While most lens boards are flat, some are recessed to accommodate wider focal length lenses which must be positioned closer to the film plane . A recessed lens ... length of a particular lens, a certain diameter of hole must be drilled in the center of the lens board to accommodate the shutter photography shutter assembly . Lens boards are typically available pre drilled by the camera manufacturer, however, if no replacement lens board is available from a camera ... 1 41.6 mm Copal 3 65 mm Copal 3s 64.5 mm Lens mounting Image graphex lens board.jpg thumb right 200px 135mm Optar lens mounted on a 0 Speed Graphic lens board Lenses are fitted to a lens ... photography shutter assembly by threading a locknut to rear of the shutter. A front lens element will thread onto the mounted shutter and if necessary, a second lens element will thread onto the rear ... with the appropriate tools. Other uses Image enlarger lens board.jpg thumb right 200px Enlarging lens ... more details
Infobox Belgium Municipality name Lens picture Lens Hainaut L tang du moulin.jpg picture legend map Lens Hainaut Belgium Map.png map legend Location of Lens in Hainaut arms flag region BE REG WAL community BE FR province BE PROV HT arrondissement Arrondissement of Mons Mons nis 53046 pyramid date 0 19 20 64 65 foreigners foreigners date mayor Ghislain Moyart PS majority Socialist Party francophone Belgium PS , Reformist Movement MR postal codes 7870 telephone area 065 web http www.lens.be www.lens.be lat deg 50 lat min 33 lon deg 03 lon min 54 Lens is a Wallonia Walloon municipality located in the Belgium Belgian province of Hainaut province Hainaut . In 2007 its population was 4042. ref http statbel.fgov.be downloads pop200701com.xls Werkelijke bevolking per gemeente op 1 januari 2007 Population de droit par commune au 1 janvier 2007 .xls ref The total area is 49.42 km which gives a population density of 80 inhabitants per km . It is located at 50 33 North, 03 54 East, alongside the N56 road Belgium N56 road . ref http statbel.fgov.be pub d1 p120 nl.xls Geografische co rdinaten van de gemeenten .xls ref References Reflist Hainaut Hainaut geo stub Category Municipalities of Hainaut province br Lens Belgia bg ca Lens B lgica de Lens Belgien eo Lens Belgio fa fr Lens Belgique it Lens Belgio nl Lens Belgi pt Lens B lgica ro Lens Belgia ru simple Lens Belgium sk Lens Belgicko vi Lens, Hainaut vo Lens Belg n wa Linse war Lens, Belhika ... more details
DISPLAYTITLE Lens genus Taxobox name Lens image Illustration Lens culinaris0.jpg image width 200px image caption Lens culinaris regnum Plantae unranked divisio Angiosperms unranked classis Eudicots unranked ordo Rosids ordo Fabales familia Fabaceae subfamilia Faboideae tribus Fabeae genus Lens genus authority Mill. subdivision ranks Species subdivision Lentil Lens culinaris Lentils br Lens ervoides br Lens lamottei br Lens nigricans br td tr tr td Ref http www.ildis.org ILDIS Version 6.05 The genus Lens of the legume family Fabaceae contains four species of small, erect or climbing herb s with pinnate Leaf leaves and small inconspicuous white flower s and small flattened pods. The edible seed s of Lens species are referred to as lentil s the lentil most commonly eaten is the seed of Lens culinaris . External links http gisweb.ciat.cgiar.org GapAnalysis ?p 271 Crop Wild Relatives Gap Analysis Portal reliable information source on where and what to conserve ex situ , regarding Lens genepool DEFAULTSORT Lens Genus Category Faboideae Faboideae stub az M rcim k cins ca Lens g nere da Linse sl gten de Linsen dsb Sok rod es Lens planta fr Lens genre hy hsb Sok r d it Lens botanica ka lt L is augalas ru sv Linssl ktet vi Lens genus ... more details
Image Cylindrical lenses.jpg thumb Cylindrical lenses. Image CylindricalLenses 2.png thumb 300px Diagram showing cylindrical lenses. br A Plano Convex cylindrical lens br B Plano Concave cylindrical lens A cylindrical lens is a lens optics lens which Focus optics focus es light which passes through on to a line instead of on to a point, as a Lens optics spherical lens would. The curved face or faces of a cylindrical lens are sections of a Cylinder geometry cylinder , and focus the image passing through it onto a line parallel to the intersection of the surface of the lens and a plane tangent to it. The lens compresses the image in the direction perpendicular to this line, and leaves it unaltered in the direction parallel to it in the tangent plane . Cylindrical lenses can be used to correct astigmatism eye ocular astigmatism , although toric lens es are more commonly used. They can also potentially be used in solar water heating installations, such as a plastic pillow type solar water heater. They are used to correct the output from diode laser s, to produce a round beam from the diode s elliptical output. Sources Jacobs, Donald H. Fundamentals of Optical Engineering. McGraw Hill Book Co., 1943. Category Lenses optics stub de Zylinderlinse nl Cilindrische lens ... more details
Breathing refers to when a lens optics lens optics change the apparent focal length slightly when shifting the mechanical focus optics focus . Some often more expensive lenses are designed to lessen the degree this effect. Lens breathing does not prevent one from racking focus or follow focus following focus with this lens, but it lessens the desirability of any type of focus adjustment, since it noticeably changes the composition of the shot. Not to be confused with the suction and expulsion of air from within the lens as its internal volume changes. DEFAULTSORT Breathing Lens Category Film and video terminology Filming stub ... more details
Primary lens redirects here. See also prime lens . In photography , a secondary lens is a photographic lenslens designed to be used in conjunction with another lens, called the primary lens . A secondary lens may be designed to be used either in front of the primary lens, between it and the subject, or behind the primary lens, between it and the film. Secondary lenses are typically simpler in mechanical ... of Focus optics focus or aperture , as these are achieved by the controls on the primary lens. Lenses used in front of the primary lens Examples of secondary lenses designed to be used in front of the primary lens are Fisheye lens Fisheye adaptors Corrected wide angle lens wide angle adaptors Telephoto adaptors such as teleside converter s Close up lens es All of these typically mount on the filter ring of the primary lens. Front mounting secondary lenses are commonly used to provide wide angle and telephoto lenses for cameras which lack the facility to change the primary lens, such as consumer ... the primary lens Teleconverters main teleconverter The most common secondary lens used behind the primary lens is the teleconverter . A typical teleconverter has a male and a female lens mount of the same type, to allow it to be used between a primary lens and a camera body of the matching system. The resulting combination has a greater focal length than the primary lens alone, and the same absolute ..., and when used in this combination deliver quality comparable to the primary lens. Others are general purpose, and in use typically offer less image quality then a primary lens of the same quality ... adaptor, as the angle of view of the primary lens is matched to the film format for which is designed ... to use the primary lens for wider angles than those for which it is designed is therefore likely to cause ... lens to adapt a lens of one camera system and or film format to another. These are called active adaptors or converters. For example, a Pentax screw mount lens cannot normally be mounted on a Nikon ... more details
Image Imgageinverting 1.png thumb right Cross section of relay lens assembly System 1. Image Imageinverting 2.png thumb right Cross section of relay lens assembly System 2. Image Image erecting system.png thumb right Image erecting optical system for astronomical telescopes Erecting eyepiece . In optics, a relay lens is a lens or lens group that inverts an image and extends the optical tube. Relay lenses are found in endoscope s and periscope s for the purpose of extending the system, and before eyepiece s for the purpose of inverting an image. They may be made of one or more conventional lenses or achromatic doublet s, or a long cylindrical GRIN gradient index of refraction lens a GRIN lens . Relay lenses operate by producing intermediate planes of focus. For example, an objective lens such as an SLR lens produces an image plane where the image sensor would usually go. If you place a lens with focal length f a distance 2 f from that image plane and then put an image sensor 2 f beyond the lens, that lens will relay the first image to the second with 1 1 magnification see Lens optics Imaging properties Lens imaging properties . Ideally, this second image plane will be identical to the first, so you could put a sensor there and record the exact same image. If a longer distance is needed, this can be repeated. In practice, the lens will be an achromatic doublet . Also, for endoscope applications, where small tube diameter is desirable, most of the tube is filled with glass, with thin air gaps to allow for powered surfaces because marginal ray angle is smaller at a given numerical aperture the higher the index of refraction , this allows the relay to have higher NA for a given diameter. These are known as Hopkins rod lenses . External links Lens erecting systems. http www.tpub.com content misc manuals 2 TM 9 258 TM 9 2580106.htm Image erecting systems http i916.photobucket.com ... EBchecked topic 496947 relay lens Category Lenses Optics stub ... more details
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