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Canon EF 70-300mm Lens
The EF 70–300mm lenses are a series of telephoto zoom lenses made by Canon Inc. They have a Canon EF lens mount to work with the EOS line of cameras. Four Canon EF telephoto zoom lenses carry the 70–300mm designation. *EF 70–300mm f/4.5–5.6 DO IS USM *EF 70–300mm f/4–5.6L IS USM *EF 70–300mm f/4–5.6 IS USM *EF 70–300mm f/4–5.6 IS II USM All versions offer image stabilization (IS) and ultrasonic motor drive (USM) and have nearly the same maximum aperture of 4/4.5 to 5.6 over their entire focal range. EF 70–300mm f/4.5–5.6 DO IS USM This lens makes use of Canon's Diffractive Optics rather than a traditional lens of wholly refractive design. This allows the lens to be more compact, albeit heavier and much more expensive than a lens of conventional design. The lens contains Image Stabilization and a ring USM, which allows full-time manual focusing of the lens while using the camera in single shot mode. This lens offers good optical quality with the cavea ... [...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 lengt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lens Hood
In photography, a lens hood or lens shade is a device used on the front end of a lens to block the Sun or other light source(s) to prevent glare and lens flare. Lens hoods may also be used to protect the lens from scratches and the elements without having to put on a lens cover. The geometry of a lens hood is dependent on three parameters: the focal length of the lens, the size of the front lens element and the dimensions of the image sensor or film in the camera. Cause of lens flare Flare occurs when stray light strikes the front element of a lens and then bounces around within the lens. This stray light often comes from very bright light sources, such as the Sun, bright studio lights, or a bright white background. If a light source is in the lens' angle of view, a lens hood will hardly have any effect, but the light does not have to cause lens flare. It is sufficient that stray light from a bright light source enters the lens. Multi-layer coatings in newer lenses also help to ... [...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 ... [...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 ima ... [...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, ad ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canon EF 70-300mm F4-5
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] |
Canon EF 75–300mm Lens
Introduced in 1991, the Canon EF 75–300mm 4–5.6 lens is a telephoto zoom lens for Canon EOS single-lens reflex cameras with an EF lens mount The EF lens mount is the standard lens mount on the Canon EOS family of SLR film and digital cameras. EF stands for "Electro-Focus": automatic focusing on EF lenses is handled by a dedicated electric motor built into the lens. Mechanically, it .... There are 3 basic types of the lens: the IS USM (Image Stabilization, Ultra Sonic Motor), the USM (USM, no IS) and non-USM (no USM, no IS). All 3 types are generally considered to be low-end consumer-level lenses. The Canon EF 75–300mm f/4–5.6 IS USM Lens was Canon's first Image Stabilized lens. Even with IS it is considered a consumer-grade lens. Description The non-USM versions are generally considered very low grade consumer lenses with the USM versions only slightly superior in build quality and 'feel'. None of the versions (USM or not) support full-time manual (FTM) focusing. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion (optics)
In optics, and by analogy other branches of physics dealing with wave propagation, dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency; sometimes the term chromatic dispersion is used for specificity to optics in particular. A medium having this common property may be termed a dispersive medium (plural ''dispersive media''). Although the term is used in the field of optics to describe light and other electromagnetic waves, dispersion in the same sense can apply to any sort of wave motion such as acoustic dispersion in the case of sound and seismic waves, and in gravity waves (ocean waves). Within optics, dispersion is a property of telecommunication signals along transmission lines (such as microwaves in coaxial cable) or the pulses of light in optical fiber. Physically, dispersion translates in a loss of kinetic energy through absorption. In optics, one important and familiar consequence of dispersion is the change in the angle of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canon EF 70–200mm Lens
The EF 70–200mm lenses are a group of telephoto zoom full-frame lenses made by Canon. The lenses have an EF mount to work with the EOS line of cameras. The lens comes in seven different versions, all of which have fixed maximum aperture at all focal lengths, and are L-series lenses. * f/4L USM * f/4L IS USM * f/4L IS II USM * f/2.8L USM * f/2.8L IS USM * f/2.8L IS II USM * f/2.8L IS III USM The latest iterations of both the f/4 and the f/2.8 variants were announced on 7 June 2018. The f/4 is currently under production and the original MSRP was increased from US$1,299 to US$1,499. In March 2021, it was reported that Canon had decided to discontinue the lens. Common fields of application The f/4 USM is popular among weight-sensitive landscape photographers and hobbyists who want L lens quality without spending thousands of dollars. The f/2.8 versions are popular among event photographers and photojournalists where the lens's lower light capabilities are required. Some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canon L Lens
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 * Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canon EF 75-300mm Lens
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] |
