Image Cylindrical lenses.jpg thumb Cylindrical lenses. Image CylindricalLenses 2.png thumb 300px Diagram showing cylindrical lenses. br A Plano Convex cylindricallens br B Plano Concave cylindricallens A cylindricallens 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 cylindricallens 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 es Lente cil ndrica nl Cilindrische lens ... more details
noreferences date December 2009 Image The Life Aquatic Cylindrical Perspective.jpg right thumb 200px Example of cylindrical perspective from The Life Aquatic with Steve Zissou Cylindrical perspective is a form of Distortion optics distortion caused by fisheye lens fisheye and panoramic lens es which reproduce straight horizontal lines above and below the lens axis level as curved while reproducing straight horizontal lines on lens axis level as straight. This is also a common feature of wide angle anamorphic lens es of less than 40mm focal length in cinematography . Essentially it is just barrel distortion but only in the horizontal plane. It is an artifact of the squeezing process that anamorphic lenses do to fit widescreen images onto standard width film. See also Distortion optics Stretch o Vision DEFAULTSORT Cylindrical Perspective Category Photographic techniques Photo stub ... more details
Cylindrical drums are a category of drum instruments that include a wide range of implementations, including the bass drum and the Iranian dohol . Cylindrical drums are generally two headed and straight sided, and sometimes use a buzzing, percussive string. The Iranian dohol is a famous form of cylindrical drum. Many music area s nears in the Middle East, North Africa and Central Asia include variations on the dohol and cylindrical drum forms, including the dhol of Armenia, daval of Kurdistan and the tabl ballady of Egypt. Southeastern Europe is home to cylindrical drums like the tapan of Macedonia and the dauli of Greece. References Cite web work Drum Dojo accessdate January 22, 2007 url http www.nasehpour.com peyman id91.html title Dohol and Cylindrical Drums year 2002 author Peyman Nasehpour cite web url http www.sil.org LinguaLinks Anthropology ExpnddEthnmsclgyCtgrCltrlMtrls mMembranophones.htm title 534m Membranophones work SIL accessdate January 4, 2007 Category Drums Category Membranophones percussion instrument stub es Tambor cil ndrico ... 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 Camera 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 lb Lens lt Lens nl Lens oc Lens pms Lens pt Lens sco Lens simple Lens disambiguation sk Lens sv Lens tr Lens vo Lens ... more details
File Cylindrical joint.svg 200px thumb right Cylindrical joint seen in 3 dimensional view. A cylindrical joint is a two Degrees of freedom mechanics degrees of freedom kinematic pair used in mechanisms. ref name norton cite book last Norton first Robert L. title Design of Machinery publisher McGraw Hill Higher Education location Boston, MA year 2008 edition 4th pages 33 chapter 2 isbn 9780073121581 language English American ref Cylindrical joints provide single axis sliding function as well as a single axis rotation, providing a way for two rigid bodies to translate and rotate freely. This can be pictured by an unsecured axle mounted on a chassis, as it may freely rotate and translate. ref name Shabana cite book last Shabana first Ahmed A. title Computational Dynamics publisher John Wiley and Sons year 2001 edition 2nd pages 434 isbn 9780471053262 ref See also Degrees of freedom mechanics Kinematic pair Kinematics References reflist KinematicPair Category Kinematics Category Rigid bodies classicalmechanics stub ... more details
Taxobox name Cylindrical lanternshark image Etmopterus carteri.JPG image caption status DD status system IUCN3.1 trend regnum Animal ia phylum Chordate Chordata classis Chondrichthyes subclassis Elasmobranchii ordo Squaliformes familia Etmopteridae genus Etmopterus species E. carteri range map Etmopterus carteri distmap.png range map width 200px range map caption Range of the cylindrical lanternshark in blue binomial Etmopterus carteri binomial authority Stewart Springer S. Springer & George H. Burgess G. H. Burgess , 1985 Portal Sharks The cylindrical lanternshark , Etmopterus carteri , is a shark of the family biology family Etmopteridae found along the Caribbean coast of Colombia in South America , at depths of between 285 and 355 m. Its maximum length is 21 cm. Reproduction is presumed to be ovoviviparous , with three to 20 pups of 10 20 cm in length per litter. ref cite web url http www.science.fau.edu sharklab courses elasmobiology families Etmopteridae.pdf title The Lantern Sharks author Florida Atlantic University date 2007 ref References Reflist FishBase species genus Etmopterus species carteri month July year 2006 Leonard Compagno Compagno , Dando, & Fowler, Sharks of the World , Princeton University Press, New Jersey 2005 ISBN 0 691 12072 2 Selachimorpha D. DEFAULTSORT Cylindrical Lanternshark Category Dalatiidae ca Etmopterus carteri de Zylindrischer Laternenhai es Etmopterus carteri ... more details
The cylindrical grinder is a type of grinding machine used to shape the outside of an object. The cylindrical ... Company, 1959. 104 141. ref File Cylindrical grinder, Landis, photo 291.png thumb A cylindrical grinder. Cylindrical grinding is defined as having four essential actions The work object must be constantly .... While the majority of cylindrical grinders employ all four movements, there are grinders that only ... www.the vms.com vms other grinding other grinding 00.html . ref History The origins of the cylindrical ... boring machine and first engine lathe , respectively. The cylindrical grinder owes much of its ... for the modern day cylindrical grinder was first built in the 1830s by two men working independently ... steel. It was this desire that led to their experimentation with building a cylindrical grinder. The first ... to the cylindrical grinder displayed at the 1876 Centennial Exposition and the subsequent patent. ref ... of pioneering advances in cylindrical grinding. A man in Waltham, Massachusetts, Ambrose Webster ... pursue his belief that the cylindrical grinder is not merely a finishing tool but could be a staple of the machine shop. He founded the Norton Grinding Company, where he continue improving the cylindrical ... to the cylindrical grinder is almost identical and entangled in a sense, to the rest of machine ... marked the birth of Computer Numerical Control which once again revolutionized the ability of the cylindrical ... little to no human supervision. ref name heinrich Types There are five different types of cylindrical ... Diameter Cylindrical Grinding. The Curved Arrows refer to direction of rotation Outside diameter ... overview of Internal Diameter Cylindrical Grinding. The Curved Arrows refer to direction of rotation ... for this purpose. This form occurs in both cylindrical and surface grinding . ref name stephenson Centerless grinding Image Centerless cylindrical grinder.jpg thumb Centerless cylindrical grinder ... There are three basics ways in which an operator can interact with a cylindrical grinder. Either ... more details
Taxobox name Cylindrical lioplax image Lioplax cyclostomaformis shell.jpg image caption A 1870 drawing of the shell of Lioplax cyclostomaformis status VU status system IUCN2.3 status ref ref Bogan, A.E. 1996. http www.iucnredlist.org search details.php 12101 all Lioplax cyclostomaformis . http www.iucnredlist.org 2006 IUCN Red List of Threatened Species. Downloaded on 7 August 2007. ref regnum Animalia phylum Mollusca classis Gastropoda unranked superfamilia clade Caenogastropoda br informal group Architaenioglossa superfamilia Viviparoidea familia Viviparidae subfamilia Lioplacinae genus Lioplax species L. cyclostomaformis binomial Lioplax cyclostomaformis binomial authority Isaac Lea I. Lea , 1841 synonyms The cylindrical lioplax , scientific name Lioplax cyclostomaformis , is a species of freshwater snail with gill s and an operculum gastropod operculum , an Aquatic animal aquatic gastropod mollusk in the family biology family Viviparidae . This species is Endemism endemic to the United States . Description The gastropod shell shell is elongate, reaching about 28 millimeters mm 1.1 inches in in length. Shell color is light to dark olivaceous green externally, and bluish inside of the aperture mollusc aperture shell opening . The cylindrical lioplax is distinguished from other viviparid eggs hatch internally and the young are born as juveniles snails in the Mobile River Basin by the number of whorl mollusc whorls , and differences in size, sculpture, microsculpture, and spire mollusc spire angle. Distribution This species is Endemism endemic to the United States . No other ... records for the cylindrical lioplax exist from the Alabama River Dallas County, Alabama , Black ... pp. ref Vidrine, 1996 have found no evidence of the species or its typical habitat. The cylindrical ... Cylindrical lioplax snail Lioplax cyclostomaformis . Accessed 27 November 2008. ref Ecology Little is known of the biology or life history of the cylindrical lioplax. Habitat Habitat for the cylindrical ... more details
In mathematics , the cylindrical harmonics are a set of linear dependence linearly independent solutions to Laplace s equation Laplace s differential equation , math nabla 2 V 0 math , expressed in cylindrical coordinate system cylindrical coordinates , radial coordinate , polar angle , and z height . Each function V sub n sub k is the product of three terms, each depending on one coordinate alone. The term cylindrical harmonics is also used to refer to the Bessel function s that are cylindrical harmonics in the sense described above . Definition Each function math V n k math of this basis consists of the product of three functions math V n k rho, varphi,z P n k, rho Phi n varphi Z k,z , math where math rho, varphi,z math are the cylindrical coordinates, and n and k are constants which distinguish the members of the set from each other. As a result of the superposition principle applied to Laplace s equation, very general solutions to Laplace s equation can be obtained by linear combinations of these functions. Since all of the surfaces of constant , and z are conicoid, Laplace s equation is separable in cylindrical coordinates. Using the technique of the separation of variables , a separated solution to Laplace s equation may be written math V P rho , Phi varphi ,Z z math and Laplace s equation, divided by V , is written math frac ddot P P frac 1 rho , frac dot P P frac 1 rho 2 , frac ddot Phi Phi frac ddot Z Z 0 math The Z part of the equation is a function of z alone, and must therefore be equal to a constant math frac ddot Z Z k 2 math where k is, in general ... n k rho , math where math I n z math and math K n z math are modified Bessel function s. The cylindrical ... to the cylindrical coordinates and the limits of the summation and integration are determined by the boundary ... Point source inside a conducting cylindrical tube As an example, consider the problem of determining the potential of a unit source located at math rho 0, varphi 0,z 0 math inside a conducting cylindrical ... 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 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 in October 1981 by The Buggles on Carrere Records . ref name AIMR I Am a Camera 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 br ZTT Records ZTT Writer Geoff Downes , Trevor Horn Producer Trevor Horn Last single Elstree song Elstree br 1980 This single I Am ... , and therefore, Into the Lens features a more distinctive progressive Rock prog rock sound. When ... 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 the arrangement s a lot ... I will never let you go, and you always let the feelings show Into the Lens compared to I will never ... in music 2010 re release of Adventures in Modern Recording . The single 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 from Christopher ... 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 ... 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. Citation needed date April 2012 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
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 exactly the 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
Image Einzel lens.png thumb 300px Implementation of an Einzel lens showing the ion path. Six plates are parallel to the ion flight path with the middle plate at a particular potential. An einzel lens is a charged particle lens that focuses without changing the energy of the beam. It consists of three or more sets of cylindrical or rectangular tubes in series along an axis. It is used in ion optics to focus ion s in flight which is accomplished through manipulation of the electric field in the path of the ions. The lens elements are symmetric so the ions will regain their initial energy on exiting the lens although the velocity of the outer particles will be altered such that they converge on to the axis. This causes the outer particles to arrive at the focus optics focus intersection slightly later than the ones that travel along a straight path as they have to travel an extra distance. Theory Image Einzel lens 3d.png thumb right 250 px A perspective view of an einzel lens. The equation for the change in radial velocity for a particle as it passes between any pair of cylinders in the lens is math Delta v r int frac qE r r,z m 0v z dz math z is the axis passing through the middle of the lens. r is the direction normal to z. If the lens is constructed with cylindrical plates, the field is symmetrical around z. math E r r,z math is the magnitude of the electric field in the radial direction for a particle at a particular radial distance and distance across the gap, math m o math ... lens, thus an einzel lens can be described as two or more electrostatic immersion lenses. Solving ... to calculate the focal length of the lens. Application to television tubes Image Einzel lens ions.png thumb right 300px Path of ions as they travel through an einzel lens. The ion mass is 200 kDa accelerated ... are atypical for illustrative purposes . The einzel lens principle in a simplified form was also ... Cathode ray tube References Reflist Citation doi 10.1063 1.1686484 title Construction of an einzel lens ... more details
File Toric lens surface 2.png thumb right Toric lens surface as cap top right from a torus here with R 1.2 r . A toric lens is a lens optics lens with two different optical power powers in two orientations perpendicular to each other. One of the lens surfaces is shaped like a cap from a torus see figure at right , while the other one usually is Sphere spherical . Toric lenses are primarily used in Glasses eyeglass es, contact lens es and intraocular lens es, to correct for Astigmatism eye astigmatism . Torus File Superficie t rica.svg thumb right upright A torus results when a circle with radius r rotates around an axis lying in the same plane as the circle here the z axis at a distance ... , the torus becomes a sphere. left The toric lens The greatest radius of curvature of the toric lens ... 1 R r , where n is the index of refraction of the lens material. The smallest radius of curvature, r , corresponds to the greatest refractive power, nowrap 1 s n 1 r . Since nowrap 1 R r r , nowrap S s . The lens behaves approximately like a combination of a spherical lens with optical power s and a cylindricallens with power nowrap s S . In ophthalmology and optometry nowrap s S is called the cylinder power of the lens. ref This is used for correcting astigmatism. In this context, the term cylinder ... with a popular assumption, the toric lens is not an Spheroid ellipsoid of revolution . Working Ray ... of the eye. Atoric lens With modern computer controlled design, grinding and polishing techniques ... from the toric shape. This is called an atoric lens literally, non toric lens . ref http www.laramyk.com wp content uploads 2010 05 Principles of Atoric Lens Design.pdf Meister, D. Principles of Atoric Lens Design , in Lens Talk , Vol. 27, No. 3 Jan. 1998 ref ref http www.oculist.net downaton502 ... to toric lenses in the same way that aspheric lens es are related to spherical lenses. References references Category Geometrical optics Category Corrective lenses de Torische Linse nl Torische lens ... more details
axis may then not pass through the physical centre of the lens. Toric lens Toric or sphero cylindrical ... Back focal plane Bokeh Cardinal point optics Corrective lensCylindricallens Eyepiece F number Fresnel ...Other uses Lens disambiguation Lens No, this dablink is not superfluous. Some of the listed other uses of lens are ambiguous with lens optics . File BiconvexLens.jpg thumb right 250px A lens. File Lens and wavefronts.gif right frame Lenses can be used to focus light. A lens is an optics optical device ... , converging or diverging the light beam beam . Citation needed date September 2010 A simple lens consists of a single optical element. A compound lens is an array of simple lenses elements with a common ... lenses for instance, a microwave lens can be made from paraffin wax . The variant spelling lense ... lens File Nimrud lens British Museum.jpg thumb right The Nimrud lens The word lens comes from the Latin name of the lentil , because a double convex lens is lentil shaped. The genus of the lentil plant is Lens genus Lens , and the most commonly eaten species is Lens culinaris . The lentil plant also gives its name to a Lens geometry geometric figure . The oldest lens artifact is the Nimrud lens , which is over three thousand years old, dating back to ancient Assyria . ref name Nimrud lens Cite ... sunlight. ref name Nimrud lens ref Cite journal journal Die Fortschritte der Physik publisher Deutsche ... lens and decomposed glass found in Niniveh language German url http books.google.com ?id bHwEAAAAYAAJ&pg RA1 PA355&dq niniveh lens ref Assyrian craftsmen made intricate engravings, and could have used such a lens in their work. Another early reference to magnification dates back to ancient Egypt ian ... play The Clouds 424 BC mentioning a burning glass a Types of lenses biconvex lens used to focus ... is arguably the earliest written reference to a corrective lens Nero was said to watch the gladiator ... comparable to that of 1950s aspheric lens es. The Viking lenses were capable of concentrating ... more details
File 20100105 MultifocalGlass.jpg thumb right View through a progressive lens at some distance. In normal ... prescription lenses , and varifocal or multifocal lenses , are corrective lens es used in glasses ... by a gradient of increasing optical power lens power , added to the wearer s correction ..., 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 dioptre ... ref Aves patent included the progressive lens design and the manufacturing process. However this was unlike modern PALs. It consisted of a conical back surface and a cylindrical front with opposing axes ... intermediate steps H. Newbold appears to have designed a similar lens to Aves around 1913 , there is evidence .... Irving Rips at Younger Optics developed the first commercially viable blended lens in 1955 called the Younger Seamless Bifocal. The Varilux lens was the first PAL of modern design. It was developed ... as an occupational lens, or to offer enlarged near and intermediate view areas. Since the 1980s ... of surfaces, allowing greater design control Extensive wearer trials Improved manufacturing and lens metrologic technology Today the complex surfaces of a progressive lens can be cut and polished ... the lens came to market. Advantages and use Wearers can adjust the additional lens power ... part of the vertical progression The lens location of the correct addition power for the viewing ... on the lens surface of a progressive lens appears more youthful since the single vision lenses ... can use the optimization principle, which is based on linearization and represents the lens surface using special spline functions. The lens power progressively increases between the high power and low power region of the lens. This specialized lens surface provides an accurate power distribution for both ... more details
Spherical fresnel lens This fresnel lens is equivalent to a normal spherical lens . Cylindrical fresnel lens This fresnel lens is equivalent to a normal cylindricallens . Linear fresnel lens Linear ...Image Lentille de fresnel.jpg thumb upright Lighthouse Fresnel lens, on display at the Mus e national de la Marine A Fresnel lens IPAc en f r e n l respell fray NEL or IPAc en f r z n l respell FREZ nel is a type of lens optics lens originally developed by France French physics physicist Augustin ... focal length without the mass and volume of material that would be required by a lens of conventional design. Compared to conventional bulky lenses, the Fresnel lens is much thinner, larger, and flatter ... over much greater distances. History The idea of creating a thinner, lighter lens by making it with separate ... . ref http search.eb.com eb article 9035385 Fresnel lens. Encyclop dia Britannica . 2005. Encyclop dia ... such a lens from a single thin piece of glass. ref name appleton cite book title Appleton s dictionary ... 1874 page 609 url http books.google.com books?id ti9VAAAAMAAJ&pg PA609&dq fresnel lens burning buffon ... for the development of the multi part lens for use in lighthouses. According to Smithsonian magazine Smithsonian magazine, the first Fresnel lens was used in 1823 in the Cordouan lighthouse at the mouth .... http libproxy.uncg.edu 2088 servlet BioRC Science Makes a Better Lighthouse Lens. Smithsonian ... multiple image width 200 footer image1 Fresnel lighthouse lens diagram.png alt1 How a Fresnel lens focuses light caption1 How a Fresnel lens focuses light image2 Fresnel lens.svg alt2 1 Cross section of a Fresnel len, 2 Cross section of a conventional lens caption2 1 Cross section of a Fresnel lens br 2 Cross section of a conventional Lens optics Types of simple lenses plano convex lens of equivalent power The Fresnel lens reduces the amount of material required compared to a conventional spherical lens by dividing the lens into a set of concentric annular sections known as Fresnel zone s . In theory ... more details
Image Sq3d Feuille lenticulaire.jpg thumb right A series of cylindrical lenses molded in a plastic substrate A lenticular lens is an array of magnifying lenses, designed so that when viewed from slightly ... lens. This process can be used to create various frames of animation for a motion effect , offsetting ... lenses are sometimes used as corrective lens es for improving vision. A bifocal lens could be considered ... farsightedness , a condition often created by cataract surgery when lens implant s are not possible ... the optical power power of the lens is concentrated in a small area in the center. In appearance, such a lens ... surface or carrier lens has little or no power and is there merely to fill up the rest of the eyeglass frame and to hold or carry the lenticular portion of the lens. This portion is typically 40 ... of eyeglass lens is the myodisc , sometimes termed a minus lenticular lens, used for very high negative myopia myopic corrections. More aesthetic aspheric lens designs are sometimes fitted. ref Cite book ... 3D television s, using lenticular lens systems to avoid the need for special spectacles. One of these, Chinese ... through the correct lenticule. Angle within the lens Image sq3d angle refraction.gif right The diagram at right shows in green the most extreme ray within the lenticular lens that will be refraction refracted correctly by the lens. This ray leaves one edge of an image strip at the lower right and exits ... between the extreme ray and the surface normal normal at the point where it exits the lens, math p ... of curvature of the lenticule, math e math is the thickness of the lenticular lens math h math is the thickness of the substrate below the curved surface of the lens, and math n math is the lens ... of the lenticule, and math f r sqrt r 2 left p over 2 right 2 math . Angle outside the lens Image sq3d angle indice.gif right The angle outside the lens is given by refraction of the ray determined above ... between the extreme ray and the normal outside the lens. From Snell s Law , math I arcsin ... more details
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 ... steps 0.125 D . Components of a sphero cylindrical correction Sphere component Each power specification ... and the cylindrical component describes the most convergent. In the latter, the cylinder power is a number ... number. For example a lens with sphere, cylinder of 2.25, 1.50 would convert to 3.75, 1.50 . Axis ... this, think of a soft drink can, or other cylindrical object. Note how the curvature is 90 ... powers almost always separated by 90 , the axis is also the location of the sphere component. If the lens ... cylindrical correction in focus In summary, regardless of whether plus or minus cylinder notation ... are horizontal 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 ... and near vision see Lens types Lens Types below . Infrequently, prism correction prism and base ... object bigger, the main advantage comes from the power of the lens. Over the counter readers .... Lens types Single vision File Young Somali man2a.jpg thumb right A young Somali people Somali ... or correction over the entire area of the lens. Single lenses in CR 39 plastic come finished and unfinished ... more details
refimprove date August 2010 A bored cylindrical Lock device lock is one in which two holes are bored, perpendicular to one another, into the door . A large hole is bored into the door face and a smaller crossbore hole is bored into the door edge, as opposed to a mortise lock prep cut into the edge of the door. Typically, the face hole is sized from 1.5 inches to 2.125 inches 3.8 to 5.4 cm and is centered at 2.375 inches or 2.75 inches 6.0 cm or 7.0 cm from the leading edge of the door, this distance is referred to as the backset. Other, less popular, backsets are at 3.75 and 5 inches 9.5 and 12.7 cm . Residential doors are normally prepared for a 2.375 inch 6.0 cm backset and commercial doors at a 2.75 inch 7 cm backset. History The cylindrical lock was invented by Walter Schlage ref Name Derdak cite book title International Directory of Company Histories, Volume 82 last Derdak & Grant first authorlink coauthors Thomas Derdak, Tina Grant year 2006 publisher St. James Press location University of California isbn 1558625860 page 330 pages url http books.google.com books?id V K6AAAAIAAJ&q 22Bored cylindrical lock 22&dq 22Bored cylindrical lock 22 ref in 1909 citation needed date August 2010 . The bored cylindrical lock arose from a need for a more cost effective method of locking doors. The previous norm, the mortise lock , is a more complex device, and its higher manufacturing cost as well as its more labor intensive installation make the bored cylindrical lock an ideal substitute, both in price and functionality. Currently The great majority of locks now in use on residences in North America are a variation of the cylindrical lock and are known as tubular chassis locks . Generally, they are not as strong as a cylindrical lock. Images Image Mis fotos de celular 019.jpg 300px Image Electronic lock yl88.jpg 300px References reflist Category Locks tech stub ... more details
File Cylindrical equal area projection SW.jpg 450px thumb Cylindrical equal area projection of the world ... thumb The Lambert cylindrical equal area projection with Tissot s indicatrix of deformation File Cylindrical Equal Area Projection Oblique Case Map of the World.png 450px thumb Cylindrical equal area projection with oblique orientation In cartography , the cylindrical equal area projection is a family of Map projections Cylindricalcylindrical , Map projection Equal area equal area map projection s. Cylindrical projections Main Map projection Cylindrical l1 Cylindrical map projection The term normal cylindrical projection is used to refer to any projection in which Meridian geography meridians ..., and subsequently unfolding the cylinder. By the geometry of their construction, cylindrical ... cylindrical projections, and is given by the Trigonometric function secant of the latitude as a multiple of the equator s scale. The various cylindrical projections are distinguished from each other solely by their north south stretching where latitude is given by The only cylindrical projections ... cosine equal area cylindrical with many named specializations such as Gall Peters projection Gall Peters or Gall orthographic, Behrmann projection Behrmann , and Lambert cylindrical equal area projection Lambert cylindrical equal area . This divides north south distances by a factor equal to the secant of the latitude, preserving area but heavily distorting shapes. Any particular cylindrical ... the east west scale matches the north south scale. Description Formulae All cylindrical equal area ... Mercator s projection. ref ref Weisstein, Eric W. Cylindrical Equal Area Projection. From MathWorld ... phi 0 , math math pi cos phi 0 2 , math Base projection for all the others. Lambert cylindrical equal ... math approx 1.3 math History The invention of the Lambert cylindrical equal area projection is attributed ... cite web last Mulcahy first Karen authorlink coauthors title Cylindrical Projections work publisher ... 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
Given a set S of polynomials in R sup n sup , the Cylindrical algebraic decomposition algorithm finds a decomposition of R sup n sup into cells on which each polynomial has constant sign. This decomposition is cylindrical in the following sense If 1 k n and is the projection from R sup n sup onto R sup n k sup consisting in removing the k last coordinates, then for every cells c and d , one has either c d or c d . This algorithm, introduced by Georges E. Collins in 1975 gives an effective version of Tarski s real quantifier elimination and Tarski Seidenberg theorem , which is efficient enough for being implemented on a computer. It is one of the most important algorithms of computational real algebraic geometry . References Basu, Saugata Pollack, Richard Roy, Marie Fran oise Algorithms in real algebraic geometry. Second edition. Algorithms and Computation in Mathematics, 10. Springer Verlag, Berlin, 2006. x 662 pp. ISBN 978 3 540 33098 1 3 540 33098 4 Strzebonski, Adam. http mathworld.wolfram.com CylindricalAlgebraicDecomposition.html Cylindrical Algebraic Decomposition from MathWorld . http planning.cs.uiuc.edu node292.html Cylindrical Algebraic Decomposition in Planning algorithms by Steven M. LaValle. Accessed 13 July 2007 Category Algebra Category Real algebraic geometry Algebra stub ... more details
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 ... in the form of bifocals , trifocals , vari focals, and cylindrical components for Astigmatism eye astigmatism ... other corrective lens lenses for vision correction , aspheric lenses can be categorized as convex or concave. Convex aspheric curvatures are used in many presbyopia presbyopic Progressive lens vari ... more details
Image Coord system CY 1.svg thumb 240px A cylindrical coordinate system with origin O , polar axis A , and longitudinal ... 130 , and height z 4. A cylindrical coordinate system is a three dimensional ... plane and the axis. The axis is variously called the cylindrical or longitudinal axis, to differentiate ... . Physics of Plasmas, volume 9, issue 6, 2786 2797. doi 10.1063 1.1465420 nowiki ... nowiki in cylindrical .... doi 10.1103 PhysRevLett.78.1460 nowiki ... nowiki where r , , and z are cylindrical coordinates nowiki ... nowiki as a function of axial position nowiki ... nowiki ref Cylindrical coordinates are useful ... wire, and so on. It is sometimes called cylindrical polar coordinate ref J. E. Szymanski, Basic ... onepage&q 22Cylindrical 20polar 20coordinate 22&f false page 170 ref and polar cylindrical coordinate ... page 3 ref and is sometime used to specify the position of stars in a galaxy galactocentric cylindrical ..., 431 pages http books.google.co.uk books?id N8Hngab5liQC&lpg PA37&dq cylindrical 20polar 20coordinate 20galaxy&pg PA37 v onepage&q cylindrical 20polar 20coordinate 20galaxy&f false page 37 ref Definition .... The height z is the signed distance from the chosen plane to the point P. Unique cylindrical coordinates As in polar coordinates, the same point with cylindrical coordinates , , z has infinitely ... , such as &minus 180 , 180 or 0,360 . Conventions The notation for cylindrical coordinates is not uniform ... often denoted r , the azimuth by or t , and the third coordinate by h or if the cylindrical axis is considered horizontal x , or any context specific letter. File Cylindrical coordinate surfaces.png thumb 240px right The Coordinate system Coordinate surface coordinate surfaces of the cylindrical ... coordinates of P are roughly 1.0, 1.732, 1.0 . File Cylindrical coordinate surfaces.gif right thumb 480px Cylindrical Coordinate Surfaces. The three orthogonal components, green , red , and z blue ... conversions The cylindrical coordinate system is one of many three dimensional coordinate systems ... more details
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