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Teleside Converter
A teleside converter (also known as a telephoto conversion lens or a front mount teleconverter) is a secondary lens which is mounted on the front of a photographic lens to increase the effective focal length of the lens they are attached to. They are used on cameras and video cameras with non–interchangeable lenses to increase the magnification of the image. Their design is usually that of an afocal Galilean telescope that alters the width of the entering beam of light without affecting the divergence of the beam, so they can change the effective focal length 1 to 3 times without increasing focal ratio. The down side to teleside converters is they will vignette the image on the wide angle setting if used on a zoom lens. Minimum Focal Length without vignetting will increase inline with higher power of the teleside converter. Before vignetting appears (four black corners), light fall-off will appear first and in general shooting this light fall-off may not be noticeable. The other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleconverter
A teleconverter (sometimes called tele extender) is a secondary lens mounted between a camera and a photographic lens which enlarges the central part of an image obtained by the lens. For example, a 2× teleconverter for a 35 mm camera enlarges the central 12×18 mm part of an image to the size of 24×36 mm in the standard 35 mm film format. Teleconverters are typically made in 1.4×, 1.7×, 2× and 3× variants, with 1.4× and 2× being the most common. A 2× teleconverter doubles the apparent focal length of a given lens. Teleconverters also decrease the intensity of the light that reaches the film plane (or sensor) by the square of its magnification. A 2× teleconverter reduces the light to 1/4, doubles the focal ratio and halves the resolution of the master lens it is connected to. This, however, does not necessarily halve the resolution of the digital image. A closely related device reduces the focal length. It is generally marketed under the name speed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleconverter
A teleconverter (sometimes called tele extender) is a secondary lens mounted between a camera and a photographic lens which enlarges the central part of an image obtained by the lens. For example, a 2× teleconverter for a 35 mm camera enlarges the central 12×18 mm part of an image to the size of 24×36 mm in the standard 35 mm film format. Teleconverters are typically made in 1.4×, 1.7×, 2× and 3× variants, with 1.4× and 2× being the most common. A 2× teleconverter doubles the apparent focal length of a given lens. Teleconverters also decrease the intensity of the light that reaches the film plane (or sensor) by the square of its magnification. A 2× teleconverter reduces the light to 1/4, doubles the focal ratio and halves the resolution of the master lens it is connected to. This, however, does not necessarily halve the resolution of the digital image. A closely related device reduces the focal length. It is generally marketed under the name speed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Lens
In photography, a secondary lens or accessory lens is a lens 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 design than other photographic lenses. Normally but not always there is no provision for control of 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 adaptors * Corrected wide angle adaptors * Telephoto adaptors such as teleside converters * Close-up lenses All of these lens 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium Format Camera
Medium format has traditionally referred to a film format in photography and the related cameras and equipment that use film. Nowadays, the term applies to film and digital cameras that record images on media larger than the used in 35 mm photography (though not including 127 sizes), but smaller than (which is considered large format photography). In digital photography, medium format refers either to cameras adapted from medium-format film photography uses or to cameras making use of sensors larger than that of a 35 mm film frame. Some of the benefits of using medium-format digital cameras include higher resolution sensors, better low-light capabilities compared to a traditional 35mm DSLR, and a wider dynamic range. Characteristics Medium-format cameras made since the 1950s are generally less automated than smaller cameras made at the same time. For example, autofocus became available in consumer 35 mm cameras in 1977, but did not reach medium format until ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point-and-shoot Camera
A point-and-shoot camera, also known as a compact camera and sometimes abbreviated to P&S, is a still camera designed primarily for simple operation. Most use focus free lenses or autofocus for focusing, automatic systems for setting the exposure options, and have flash units built in. They are popular for vernacular photography by people who do not consider themselves photographers but want easy-to-use cameras for snapshots of vacations, parties, reunions and other events. Most of these compact cameras use small 1/2.3" image sensors, but since 2008, a few non-interchangeable lens compact cameras use a larger sensor such as 1" and even APS-C, such as the Fujifilm X100 series, or full frame format such as the Sony Cyber-shot DSC-RX1 series. They prioritize intelligent Auto, but some high end point-and-shoot cameras have PASM (program, aperture priority, shutter priority, and manual modes) on the mode dial, raw image format, and hot shoe. None have interchangeable lenses, but s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridge Camera
Bridge cameras are cameras that fill the niche between relatively simple point-and-shoot cameras and interchangeable-lens cameras such as mirrorless cameras and single-lens reflex cameras (SLRs). They are often comparable in size and weight to the smallest digital SLRs (DSLR), but lack interchangeable lenses, and almost all digital bridge cameras lack an optical viewfinder system. The phrase "bridge camera" has been in use at least since the 1980s, and continues to be used with digital cameras. The term was originally used to refer to film cameras which "bridged the gap" between point-and-shoot cameras and SLRs. Like other cameras, most current bridge cameras are digital. These cameras typically feature full manual controls over shutter speed, aperture, ISO sensitivity, color balance and metering. Generally, their feature sets are similar to consumer DSLRs, except for a smaller range of ISO sensitivity because of their typically smaller image sensor. Many bridge cameras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camcorder
A camcorder is a self-contained portable electronic device with video and recording as its primary function. It is typically equipped with an articulating screen mounted on the left side, a belt to facilitate holding on the right side, hot-swappable battery facing towards the user, hot-swappable recording media, and an internally contained quiet optical zoom lens. The earliest camcorders were tape-based, recording analog signals onto videotape cassettes. In 2006, digital recording became the norm, with tape replaced by storage media such as mini-HD, microDVD, internal flash memory and SD cards. More recent devices capable of recording video are camera phones and digital cameras primarily intended for still pictures, whereas dedicated camcorders are often equipped with more functions and interfaces than more common cameras, such as an internal optical zoom lens that is able to operate silently with no throttled speed, whereas cameras with protracting zoom lenses commonly thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Camera
A video camera is an optical instrument that captures videos (as opposed to a movie camera, which records images on film). Video cameras were initially developed for the television industry but have since become widely used for a variety of other purposes. Video cameras are used primarily in two modes. The first, characteristic of much early broadcasting, is live television, where the camera feeds real time images directly to a screen for immediate observation. A few cameras still serve live television production, but most live connections are for security, military/tactical, and industrial operations where surreptitious or remote viewing is required. In the second mode the images are recorded to a storage device for archiving or further processing; for many years, videotape was the primary format used for this purpose, but was gradually supplanted by optical disc, hard disk, and then flash memory. Recorded video is used in television production, and more often surveillance and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prosumer
A prosumer is an individual who both consumes and produces. The term is a portmanteau of the words '' producer'' and ''consumer''. Research has identified six types of prosumers: DIY prosumers, self-service prosumers, customizing prosumers, collaborative prosumers, monetised prosumers, and economic prosumers. The terms ''prosumer'' and ''prosumption'' were coined in 1980 by American futurist Alvin Toffler, and were widely used by many technology writers of the time. Technological breakthrough and a rise in user participation blurs the line between production and consumption activities, with the consumer becoming a prosumer. Definitions and contexts Prosumers have been defined as "individuals who consume and produce value, either for self-consumption or consumption by others, and can receive implicit or explicit incentives from organizations involved in the exchange." The term has since come to refer to a person using commons-based peer production. In the digital and online wo ... [...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] |
Secondary Lens
In photography, a secondary lens or accessory lens is a lens 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 design than other photographic lenses. Normally but not always there is no provision for control of 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 adaptors * Corrected wide angle adaptors * Telephoto adaptors such as teleside converters * Close-up lenses All of these lens 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
