|
Canon EF-S 55–250mm Lens
The Canon EF-S 55–250mm 4–5.6 IS lenses are a series of telephoto zoom lenses for Canon EOS digital single-lens reflex cameras with a Canon EF-S lens mount. All versions of the lens provide a 35 mm equivalent focal length of 88–400mm, and are advertised by Canon as providing four-stop image stabilization. Additionally, it has a high maximum magnification ratio for a non-macro lens. The first lens was released in America in mid-April 2008 for a retail price of US$255, and advertised as a companion to the Canon EF-S 18–55mm IS. The Mark II version of the lens was announced June 2011, identical in specification to the previous version and featuring exactly the same optics and IS system but with a revised external design. In August 2013 a new version of the lens was announced, featuring a revised optical formula and Canon's STM (stepping motor A stepper motor, also known as step motor or stepping motor, is a brushless DC electric motor that divides a full rotation into ... [...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] |
Canon EFS 55-250 STM
Canon or Canons may refer to: Arts and entertainment * Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base * Literary canon, an accepted body of works considered as high culture ** Western canon, the body of high culture literature, music, philosophy, and works of art that is highly valued in the West * Canon of proportions, a formally codified set of criteria deemed mandatory for a particular artistic style of figurative art * Canon (music), a type of composition * Canon (hymnography), a type of hymn used in Eastern Orthodox Christianity. * ''Canon'' (album), a 2007 album by Ani DiFranco * ''Canon'' (film), a 1964 Canadian animated short * ''Canon'' (game), an online browser-based strategy war game * ''Canon'' (manga), by Nikki * Canonical plays of William Shakespeare * ''The Canon'' (Natalie Angier book), a 2007 science book by Natalie Angier * ''The Canon'' (podcast), concerning film Brands and enterprises * Cano ... [...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] |
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] |
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] |
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] |
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] |
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] |
Macro Photography
Macro photography (or photomacrography or macrography, and sometimes macrophotography) is extreme close-up photography, usually of very small subjects and living organisms like insects, in which the size of the subject in the photograph is greater than life size (though ''macrophotography'' also refers to the art of making very large photographs). By the original definition, a macro photograph is one in which the size of the subject on the negative or image sensor is life size or greater. In some senses, however, it refers to a finished photograph of a subject that is greater than life size. The ratio of the subject size on the film plane (or sensor plane) to the actual subject size is known as the reproduction ratio. Likewise, a macro lens is classically a lens capable of reproduction ratios of at least 1:1, although it often refers to any lens with a large reproduction ratio, despite rarely exceeding 1:1. Apart from technical photography and film-based processes, where the s ... [...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] |
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] |
Full-frame Digital SLR
A full-frame DSLR is a digital single-lens reflex camera (DSLR) with a 35 mm image sensor format (). Historically, 35 mm was one of the standard film formats, alongside larger ones, such as medium format and large format. The full-frame DSLR is in contrast to full-frame mirrorless interchangeable-lens cameras, and DSLR and mirrorless cameras with smaller sensors (for instance, those with a size equivalent to APS-C-size film), much smaller than a full 35 mm frame. Many digital cameras, both compact and SLR models, use a smaller-than-35 mm frame as it is easier and cheaper to manufacture imaging sensors at a smaller size. Historically, the earliest digital SLR models, such as the Nikon NASA F4 or Kodak DCS 100, also used a smaller sensor. Kodak states that 35 mm film (note: in "Academy format", 21.0 mm × 15.2 mm) has the equivalent of 6K horizontal resolution, according to a senior vice president of IMAX. This equates to 10K horizontal resolution in full- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
