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Nikon F 70-210mm Lens
The 70-210mm lens is a telephoto lens, telephoto zoom lens, zoom photographic lens, lens made by Nikon. The lens has an Nikon F-mount, F-mount to work with all compatible Nikon SLRs and DSLRs. As opposed to the various Nikon F 80-200mm lens, f/2.8 versions of the 70-210 Focal length, the f/4 and slower versions of such lenses are marketed to amateurs, accounting for their price. However, the Nikkor AF 70-210 f/4 variant is a two-touch system (dedicated focus and zoom rings), compared to the rest of the lens range, which utilizes a one-touch (push-pull) system for focusing and zooming. The lens comes in five different versions. * 4.5-5.6 * 4 Series E * 4 AF * 4-5.6 AF * 4-5.6 AF-D Specifications See also *Nikon F 80-200mm lens *Canon EF 70–210mm lens References External links Unofficial Nikon Archive by ''Photography in Malaysia'' {{DEFAULTSORT:70-210mm lens Nikon F-mount lenses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephoto Lens
A telephoto lens, in photography and cinematography, is a specific type of a long-focus lens in which the physical length of the lens is shorter than the focal length. This is achieved by incorporating a special lens group known as a ''telephoto group'' that extends the light path to create a long-focus lens in a much shorter overall design. The angle of view and other effects of long-focus lenses are the same for telephoto lenses of the same specified focal length. Long-focal-length lenses are often informally referred to as ''telephoto lenses'', although this is technically incorrect: a telephoto lens specifically incorporates the telephoto group. Telephoto lenses are sometimes broken into the further sub-types of short telephoto (85–135 mm in 35 mm film format), medium telephoto: (135–300 mm in 35 mm film format) and super telephoto (over 300 mm in 35 mm film format) . Construction In contrast to a telephoto lens, for any given focal len ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yes Check
Yes or YES may refer to: * An affirmative particle in the English language; see yes and no Education * YES Prep Public Schools, Houston, Texas, US * YES (Your Extraordinary Saturday), a learning program from the Minnesota Institute for Talented Youth * Young Eisner Scholars, in Los Angeles, New York City, Chicago, and Appalachia, US * Young Epidemiology Scholars, US Technology * yes (Unix), command to output "y" or a string repeatedly * Philips :YES, a 1985 home computer * Yes! Roadster, a German sports car Transportation * Yasuj Airport, Iran, IATA airport code * YES Airways, later OLT Express, Poland Organization * Yale Entrepreneurial Society, US * YES Snowboards * The YES! Association, a Swedish artist collective * Yes! Youth Movement, Russia * Young European Socialists formally ECOSY * Youth Empowerment Scheme, a children's charity, Belfast, Northern Ireland * Youth Energy Squad (Y.E.S) * YES (Lithuanian political party) Literature * ''Yes!'' (Hong Kong magazi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Dollar
The United States dollar ( symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official currency of the United States and several other countries. The Coinage Act of 1792 introduced the U.S. dollar at par with the Spanish silver dollar, divided it into 100 cents, and authorized the minting of coins denominated in dollars and cents. U.S. banknotes are issued in the form of Federal Reserve Notes, popularly called greenbacks due to their predominantly green color. The monetary policy of the United States is conducted by the Federal Reserve System, which acts as the nation's central bank. The U.S. dollar was originally defined under a bimetallic standard of (0.7735 troy ounces) fine silver or, from 1837, fine gold, or $20.67 per troy ounce. The Gold Standard Act of 1900 linked the dollar solely to gold. From 1934, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suggested Retail Price
The list price, also known as the manufacturer's suggested retail price (MSRP), or the recommended retail price (RRP), or the suggested retail price (SRP) of a product is the price at which its manufacturer notionally recommends that a retailer sell the product. Suggested pricing methods may conflict with competition theory, as they allow prices to be set higher than would be established by supply and demand. Resale price maintenance—fixing prices—goes further than suggesting prices, and is illegal in many countries. Retailers may charge less than the suggested retail price, depending upon the actual wholesale cost of each item, usually purchased in bulk from the manufacturer, or in smaller quantities through a distributor. The suggested price is sometimes unrealistically high, so the seller can appear to be offering a discount. List price often cannot be compared directly internationally as products may differ in detail, sometimes due to different regulations, and list pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diaphragm (optics)
In optics, a diaphragm is a thin opaque structure with an opening (aperture) at its center. The role of the diaphragm is to ''stop'' the passage of light, except for the light passing through the ''aperture''. Thus it is also called a stop (an aperture stop, if it limits the brightness of light reaching the focal plane, or a field stop or flare stop for other uses of diaphragms in lenses). The diaphragm is placed in the light path of a lens or objective, and the size of the aperture regulates the amount of light that passes through the lens. The centre of the diaphragm's aperture coincides with the optical axis of the lens system. Most modern cameras use a type of adjustable diaphragm known as an iris diaphragm, and often referred to simply as an iris. See the articles on aperture and f-number for the photographic effect and system of quantification of varying the opening in the diaphragm. Iris diaphragms versus other types A natural optical system that has a diaphragm an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angle Of View
The angle of view is the decisive variable for the visual perception of the size or projection of the size of an object. Angle of view and perception of size The perceived size of an object depends on the size of the image projected onto the retina. The size of the image depends on the angle of vision. A near and a far object can appear the same size if their edges produce the same angle of vision. With an optical device such as glasses or binoculars, microscope and telescope the angle of vision can be widened so that the object appears larger, which is favourable for the resolving power of the eye (see visual angle). Angle of view in photography In photography, angle of view (AOV) describes the angular extent of a given scene that is imaged by a camera. It is used interchangeably with the more general term field of view. It is important to distinguish the angle of view from the angle of coverage, which describes the angle range that a lens can image. Typically the image ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filter (photography)
In photography and cinematography, a filter is a camera accessory consisting of an optical filter that can be inserted into the optical path. The filter can be of a square or oblong shape and mounted in a holder accessory, or, more commonly, a glass or plastic disk in a metal or plastic ring frame, which can be screwed into the front of or clipped onto the camera lens. Filters modify the images recorded. Sometimes they are used to make only subtle changes to images; other times the image would simply not be possible without them. In monochrome photography, coloured filters affect the relative brightness of different colours; red lipstick may be rendered as anything from almost white to almost black with different filters. Others change the colour balance of images, so that photographs under incandescent lighting show colours as they are perceived, rather than with a reddish tinge. There are filters that distort the image in a desired way, diffusing an otherwise sharp image, addin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An optical system typically has many openings or structures that limit the ray bundles (ray bundles are also known as ''pencils'' of light). These structures may be the edge of a lens or mirror, or a ring or other fixture that holds an optical element in place, or may be a special element such as a diaphragm placed in the optical path to limit the light admitted by the system. In general, these structures are called stops, and the aperture stop is the stop that primarily determines the ray cone angle and brightness at the image point. In some contexts, especially in photography and astronomy, ''aperture'' refers to the diameter of the aperture stop rather than the physical stop or the opening itself. For example, in a telescope, the aperture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Mark
An X mark (also known as an ex mark or a cross mark or simply an X or ex or a cross) is used to indicate the concept of negation (for example "no, this has not been verified", "no, that is not the correct answer" or "no, I do not agree") as well as an indicator (for example, in election ballot papers or in maps as an x-marks-the-spot). Its opposite is often considered to be the check mark or tick (or the O mark used in Japan and Korea). In Japanese, the X mark (❌) is called "batsu" (ばつ) and can be expressed by someone by crossing their arms. It is also used as a replacement for a signature for a person who is blind or illiterate and thus cannot write their name. Typically, the writing of an X used for this purpose must be witnessed to be valid. As a verb, to X (or ex) off/out or to cross off/out means to add such a mark. It is quite common, especially on printed forms and document, for there to be squares in which to place x marks, or interchangeably checks. It is also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoom Lens
A zoom lens is a mechanical assembly of lens elements for which the focal length (and thus angle of view) can be varied, as opposed to a fixed-focal-length (FFL) lens (see prime lens). A true zoom lens, also called a parfocal lens, is one that maintains focus when its focal length changes. Most consumer zoom lenses do not maintain perfect focus, but are still parfocal designs. Most camera phones that are advertised as having optical zoom actually use a few cameras of different but fixed focal length, combined with digital zoom to make a hybrid system. The convenience of variable focal length comes at the cost of complexity – and some compromises on image quality, weight, dimensions, aperture, autofocus performance, and cost. For example, all zoom lenses suffer from at least slight, if not considerable, loss of image resolution at their maximum aperture, especially at the extremes of their focal length range. This effect is evident in the corners of the image, when displa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autofocus
An autofocus (or AF) optical system uses a sensor, a control system and a motor to focus on an automatically or manually selected point or area. An electronic rangefinder has a display instead of the motor; the adjustment of the optical system has to be done manually until indication. Autofocus methods are distinguished as active, passive or hybrid types. Autofocus systems rely on one or more sensors to determine correct focus. Some AF systems rely on a single sensor, while others use an array of sensors. Most modern SLR cameras use through-the-lens optical sensors, with a separate sensor array providing light metering, although the latter can be programmed to prioritize its metering to the same area as one or more of the AF sensors. Through-the-lens optical autofocusing is usually speedier and more precise than manual focus with an ordinary viewfinder, although more precise manual focus can be achieved with special accessories such as focusing magnifiers. Autofocus accuracy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Focal Length
The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative focal length indicates that the system diverges light. A system with a shorter focal length bends the rays more sharply, bringing them to a focus in a shorter distance or diverging them more quickly. For the special case of a thin lens in air, a positive focal length is the distance over which initially collimated (parallel) rays are brought to a focus, or alternatively a negative focal length indicates how far in front of the lens a point source must be located to form a collimated beam. For more general optical systems, the focal length has no intuitive meaning; it is simply the inverse of the system's optical power. In most photography and all telescopy, where the subject is essentially infinitely far away, longer focal length (lower opti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
