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Pentax MG
The Pentax MG is a camera that was produced by Asahi Optical Co from 1981 until 1984. The Pentax MG replaced the Pentax MV and MV1 cameras as an entry level 35mm semi-automatic camera. The Pentax MG was a manual focus, aperture priority camera, with no manual settings of speeds. The Pentax MG had an electronic focal-plane shutter from 1s to 1/1000, synchronized at 1/100. The shutter curtains were metal and had a vertical movement. However, if the batteries fail the camera still operated at 1/100s or B, thus the selector around the release button had three positions: Auto, 100X (1/100, X sync) and B. The exposure meter is center-weighted TTL type with open aperture measuring for Pentax M compatible lenses. The Pentax MG can use any Pentax K-mount and can still be used with current Pentax lenses. There was a self-timer and a hot shoe with an additional contact for dedicated Pentax flash units. The Pentax MG used 2 SR-44 batteries or equivalent to power it. The Pentax MG had a 0.87 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asahi Optical Co
Asahi (朝日, 旭, or あさひ) means "morning sun" in Japanese and may refer to: Cities * Asahi, Chiba (旭市; ''Asahi-shi'') Wards * Asahi-ku, Osaka (旭区; ''Asahi-ku'') * Asahi-ku, Yokohama (旭; ''Asahi-ku'') Towns * Asahi, Aichi (旭町; ''Asahi-chō'') * Asahi, Fukui (朝日町; ''Asahi-chō'') * Asahi, Hokkaido (朝日町; ''Asahi-chō'') * Asahi, Mie (朝日町; ''Asahi-chō'') * Asahi, Okayama (旭町; ''Asahi-chō'') * Asahi, Shimane (旭町; ''Asahi-chō'') * Asahi, Toyama (朝日町; ''Asahi-machi'') * Asahi, Yamagata (Nishimurayama) (朝日町; ''Asahi-machi'') Villages * Asahi, Gifu (朝日村; ''Asahi-mura'') * Asahi, Ibaraki (旭村; ''Asahi-mura'') * Asahi, Nagano (朝日村; ''Asahi-mura'') * Asahi, Niigata (朝日村; ''Asahi-mura'') * Asahi, Yamagata (Tagawa) (朝日村; ''Asahi-mura'') * Asahi, Yamaguchi (旭村; ''Asahi-son'') Companies * Asahi Breweries, a Japanese beverage company * '' Asahi Shimbun'', a Japanese newspaper * Asahi Producti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LEDs
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Early LEDs were often used as indicator lamps, replacing small incandescent bulbs, and in seven-segment displays. Later developments produced LEDs available in visible, ultraviolet (UV) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Products Introduced In 1981
Product may refer to: Business * Product (business), an item that serves as a solution to a specific consumer problem. * Product (project management), a deliverable or set of deliverables that contribute to a business solution Mathematics * Product (mathematics) Algebra * Direct product Set theory * Cartesian product of sets Group theory * Direct product of groups * Semidirect product * Product of group subsets * Wreath product * Free product * Zappa–Szép product (or knit product), a generalization of the direct and semidirect products Ring theory * Product of rings * Ideal operations, for product of ideals Linear algebra * Scalar multiplication * Matrix multiplication * Inner product, on an inner product space * Exterior product or wedge product * Multiplication of vectors: ** Dot product ** Cross product ** Seven-dimensional cross product ** Triple product, in vector calculus * Tensor product Topology * Product topology Algebraic topology * Cap product * Cup product * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentax SLR Cameras
is a brand name used primarily by the Japanese multinational imaging and electronics company Ricoh for DSLR cameras, lenses, sport optics (including binoculars and rifle scopes), and CCTV optics. The Pentax brand is also used by Hoya Corporation for medical products & services, TI Asahi for surveying instruments, and Seiko Optical Products for certain optical lenses. Corporate history Early history The company was founded as Asahi Kogaku Goshi Kaisha in November 1919 by Kumao Kajiwara, at a shop in the Toshima suburb of Tokyo, and began producing spectacle lenses (which it still manufactures). In 1938 it changed its name to , and by this time it was also manufacturing camera/cine lenses. In the lead-up to World War II, Asahi Optical devoted much of its time to fulfilling military contracts for optical instruments. At the end of the war, Asahi Optical was disbanded by the occupying powers, being allowed to re-form in 1948. The company resumed its pre-war activities, manufacturi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Pentax Products
The following is a partial list of products manufactured under the Pentax brand. Film cameras 35 mm SLR cameras M37 screw mount Cameras using the M37 lens mount. * Ashiflex I (1952–1953) * Asahiflex Ia (1953–1954) — also sold as the Tower 23 * Asahiflex IIb (1954–1957) — also sold as the Tower 23 * Asahiflex IIa (1955–1957) — also sold as the Tower 22 and Tower 24 M42 screw mount Cameras using the M42 lens mount, also known as the ''Pentax screw mount''. * Asahi Pentax (1957) — also sold as the Tower 26 * Asahi Pentax S (1958) — also sold as the Tower 26 * Asahi Pentax K (1958) — also sold as the Tower 29 * Asahi Pentax S2/H2 (1959) — also sold as the Honeywell Pentax H2/Honeywell Heiland Pentax H2 * Asahi Pentax S3/H3 (1960) — also sold as the Honeywell Pentax H3/Honeywell Heiland Pentax H3 * Asahi Pentax S1/H1 (1961) — also sold as the Honeywell Pentax H1/Honeywell Heiland Pentax H1 * Asahi Pentax SV/H3v (1963) — also sold as the Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adapter
An adapter or adaptor is a device that converts attributes of one electrical device or system to those of an otherwise incompatible device or system. Some modify power or signal attributes, while others merely adapt the physical form of one connector to another. Travel adapters Many countries with ties to Europe use 230-volt, 50 Hz AC mains electricity, using a variety of power plugs and sockets. Difficulty arises when moving an electrical device between countries that use different sockets. A passive electric power adapter, sometimes called a ''travel plug'' or ''travel adapter'', allows using a plug from one region with a foreign socket. As other countries supply 120-volt, 60 Hz AC, using a travel adapter in a country with a different supply poses a safety hazard if the connected device does not support both input voltages. AC-to-DC adapters An AC-to-DC power supply adapts electricity from household mains voltage (either 120 or 230 volts AC) to low-voltage DC suitable fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camera
A camera is an Optics, optical instrument that can capture an image. Most cameras can capture 2D images, with some more advanced models being able to capture 3D images. At a basic level, most cameras consist of sealed boxes (the camera body), with a small hole (the aperture) that allows light to pass through in order to capture an image on a light-sensitive surface (usually a Image sensor, digital sensor or photographic film). Cameras have various mechanisms to control how the light falls onto the light-sensitive surface. Lenses focus the light entering the camera, and the aperture can be narrowed or widened. A Shutter (photography), shutter mechanism determines the amount of time the photosensitive surface is exposed to the light. The still image camera is the main instrument in the art of photography. Captured images may be reproduced later as part of the process of photography, digital imaging, or photographic printing. Similar artistic fields in the moving-image camera dom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PENTAX MG
The Pentax MG is a camera that was produced by Asahi Optical Co from 1981 until 1984. The Pentax MG replaced the Pentax MV and MV1 cameras as an entry level 35mm semi-automatic camera. The Pentax MG was a manual focus, aperture priority camera, with no manual settings of speeds. The Pentax MG had an electronic focal-plane shutter from 1s to 1/1000, synchronized at 1/100. The shutter curtains were metal and had a vertical movement. However, if the batteries fail the camera still operated at 1/100s or B, thus the selector around the release button had three positions: Auto, 100X (1/100, X sync) and B. The exposure meter is center-weighted TTL type with open aperture measuring for Pentax M compatible lenses. The Pentax MG can use any Pentax K-mount and can still be used with current Pentax lenses. There was a self-timer and a hot shoe with an additional contact for dedicated Pentax flash units. The Pentax MG used 2 SR-44 batteries or equivalent to power it. The Pentax MG had a 0.87 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exposure Compensation
Exposure compensation is a technique for adjusting the exposure indicated by a photographic exposure meter, in consideration of factors that may cause the indicated exposure to result in a less-than-optimal image. Factors considered may include unusual lighting distribution, variations within a camera system, filters, non-standard processing, or intended underexposure or overexposure. Cinematographers may also apply exposure compensation for changes in shutter angle or film speed (as exposure index), among other factors. Many digital cameras have a display setting and possibly a physical dial whereby the photographer can set the camera to either over or under expose the subject by up to three f-stops (f-numbers) in 1/3 stop intervals. Each number on the scale (1,2,3) represents one f-stop, decreasing the exposure by one f-stop will halve the amount of light reaching the sensor. The dots in between the numbers represent 1/3 of an f-stop.Exposure Compensation"By Geoff Lawrence"/ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shutter Speed
In photography, shutter speed or exposure time is the length of time that the film or digital sensor inside the camera is exposed to light (that is, when the camera's shutter (photography), shutter is open) when taking a photograph. The amount of light that reaches the Photographic film, film or image sensor is proportional to the exposure time. of a second will let half as much light in as . Introduction The camera's shutter speed, the lens's aperture or f-stop, and the scene's luminance together determine the amount of light that reaches the film or sensor (the exposure (photography), exposure). Exposure value (EV) is a quantity that accounts for the shutter speed and the f-number. Once the sensitivity to light of the recording surface (either film or sensor) is set in numbers expressed in "Film speed#ISO, ISOs" (ex: 200 ISO, 400 ISO), the light emitted by the scene photographed can be controlled through aperture and shutter-speed to match the film or sensor sensitivity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentax Cameras
This article discusses the cameras – mainly 35 mm SLRs – manufactured by Ricoh Imaging Corp. and its predecessors, and . Pentax must not be confused with Pentax 6x7 or Pentax 67 which are 120 medium format 6x7cm film cameras. It covers from the first "Asahiflex" models in 1952 and their successor, the pivotal "Asahi Pentax" single-lens reflex camera, last made in 1997, to the present time known as "Pentax" first made in 1981. Background The period around 1950 marked the return of the Japanese photographic industry to the vigorous level of the early 1940s, and its emergence as a major exporter. The newly reborn industry had sold many of its cameras to the occupation forces (with hugely more disposable income than the Japanese) and they were well received. The Korean War saw a huge influx of journalists and photographers to the Far East, where they were impressed by lenses from companies such as Nikon and Canon for their Leica rangefinder cameras, and also by bodies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viewfinder
In photography, a viewfinder is what the photographer looks through to compose, and, in many cases, to focus the picture. Most viewfinders are separate, and suffer parallax, while the single-lens reflex camera lets the viewfinder use the main optical system. Viewfinders are used in many cameras of different types: still and movie, film, analog and digital. A zoom camera usually zooms its finder in sync with its lens, one exception being rangefinder cameras. History Before the development of microelectronics and electronic display devices, only optical viewfinders existed. Direct optical viewfinders Direct viewfinders are essentially miniature Galilean telescopes; the viewer's eye was placed at the back, and the scene viewed through the viewfinder optics. A declining minority of point and shoot cameras use them. Parallax error results from the viewfinder being offset from the lens axis, to point above and usually to one side of the lens. The error varies with distance, being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
