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Mirror Lock-up
Mirror lock-up (often abbreviated to MLU) is a feature employed in many Single Lens Reflex (SLR) cameras. It allows the operator to reduce vibration-induced motion blur during exposure. It also allows the mounting of lenses which extend into the SLR's mirror box when mounted. Reducing vibration Normal operation in an SLR camera involves flipping the mirror up out of the light-path just before the shutter opens, and then returning it when the shutter closes (although very early SLR's required the shutter to be cocked for the mirror to return). This causes vibration of the camera, particularly when the mirror slaps into the top of the mirror box. This vibration quickly dies away so the most motion blur is actually seen with short shutter times that capture multiple 'swings' of the vibration (shutter speeds of 1/2 to 1/60 second are often affected by this). While longer exposures will capture all of the vibrations, the exposure will be dominated by light captured when the camera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SLR Cross Section
SLR may refer to: Science and technology * Satellite laser ranging * Scalable Linear Recording tape drive backup * Sea level rise * Self-loading rifle or Semi-automatic rifle#Operation, semi-automatic rifle ** The UK L1A1 SLR rifle * Semi-linear resolution, a search algorithm * Sending loudness rating for microphones * Simple LR parser (Simple Left-to-right parser) * Single-lens reflex camera ** See also: Digital single-lens reflex camera (digital SLR or DSLR) * SLR (company), a virtual reality company * Service List Registry, of audiovisual services Transport * Holden Torana#A9X option, Holden Torana SLR5000 car * Mercedes-Benz 300 SLR * Mercedes-Benz SLR McLaren * Shimano#Shimano products, Shimano Linear Response, a bicycle component * Sri Lanka Railways * St. Lawrence and Atlantic Railroad reporting mark Other uses * ''Stanford Law Review'' * Statutory liquidity ratio {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-lens Reflex Camera
A single-lens reflex camera (SLR) is a camera that typically uses a mirror and prism system (hence "reflex" from the mirror's reflection) that permits the photographer to view through the lens and see exactly what will be captured. With twin lens reflex and rangefinder cameras, the viewed image could be significantly different from the final image. When the shutter button is pressed on most SLRs, the mirror flips out of the light path, allowing light to pass through to the light receptor and the image to be captured. History File:Hasselblad 1600F.jpg, Medium format SLR by Hasselblad (Model 1600F), Sweden File:Zenza BRONICA S2 with ZENZANON 100mm F2.8.JPG, Medium format SLR by Bronica (Model S2), Japan. Bronica's later model—the Bronica EC—was the first medium format SLR camera to use an electrically operated focal-plane shutter File:Asahiflex600.jpg, The 1952 (Pentax) Asahiflex, Japan's first single-lens reflex camera. File:Contaflex BW 2.JPG, The Contaflex III a single- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibration
Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin ''vibrationem'' ("shaking, brandishing"). The oscillations may be periodic function, periodic, such as the motion of a pendulum—or random, such as the movement of a tire on a gravel road. Vibration can be desirable: for example, the motion of a tuning fork, the Reed (music), reed in a woodwind instrument or harmonica, a mobile phone, or the cone of a loudspeaker. In many cases, however, vibration is undesirable, wasting energy and creating unwanted sound. For example, the vibrational motions of engines, electric motors, or any Machine, mechanical device in operation are typically unwanted. Such vibrations could be caused by Engine balance, imbalances in the rotating parts, uneven friction, or the meshing of gear teeth. Careful designs usually minimize unwanted vibrations. The studies of sound and vibration are closely related. Sound, or pressure waves, are ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motion Blur
Motion blur is the apparent streaking of moving objects in a photograph or a sequence of frames, such as a film or animation. It results when the image being recorded changes during the recording of a single exposure, due to rapid movement or long exposure. Usages / Effects of motion blur Photography When a camera creates an image, that image does not represent a single instant of time. Because of technological constraints or artistic requirements, the image may represent the scene over a period of time. Most often this exposure time is brief enough that the image captured by the camera appears to capture an instantaneous moment, but this is not always so, and a fast moving object or a longer exposure time may result in blurring artifacts which make this apparent. As objects in a scene move, an image of that scene must represent an integration of all positions of those objects, as well as the camera's viewpoint, over the period of exposure determined by the shutter speed. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exposure (photography)
In photography, exposure is the amount of light per unit area (the image plane's illuminance times the exposure time) reaching a frame of photographic film or the surface of an electronic image sensor, as determined by shutter speed, lens F-number, and scene luminance. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance in a specified region. An "exposure" is a single shutter cycle. For example, a long exposure refers to a single, long shutter cycle to gather enough dim light, whereas a multiple exposure involves a series of shutter cycles, effectively layering a series of photographs in one image. The accumulated ''photometric exposure'' (''H''v) is the same so long as the total exposure time is the same. Definitions Radiant exposure Radiant exposure of a ''surface'', denoted ''H''e ("e" for "energetic", to avoid confusion with photometric quantities) and measured in , is given by :H_\mathrm = E_\mathrmt, where *''E'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shutter (photography)
In photography, a shutter is a device that allows light to pass for a determined period, exposing photographic film or a photosensitive digital sensor to light in order to capture a permanent image of a scene. A shutter can also be used to allow pulses of light to pass outwards, as seen in a movie projector or a signal lamp. A shutter of variable speed is used to control exposure time of the film. The shutter is constructed so that it automatically closes after a certain required time interval. The speed of the shutter is controlled by a ring outside the camera, on which various timings are marked. Camera shutter Camera shutters can be fitted in several positions: * Leaf shutters are usually fitted within a lens assembly (''central shutter''), or more rarely immediately behind (''behind-the-lens shutter'') or, even more rarely, in front of a lens, and shut off the beam of light where it is narrow. *Focal-plane shutters are mounted near the focal plane and move to uncover the fil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Self Timer
A self timer is a device on a camera that gives a delay between pressing the shutter release and the shutter's firing. It is most commonly used to let the photographer to take a photo of themselves (often with a group of other people), hence the name. The self-timer is also used to reduce camera shake when taking photographs in low light or with long (telephoto) lenses. The timer's delay gives the photographer time to steady the camera before the shutter fires, and allows vibrations from the mirror flipping up (on SLRs) to die out. It also eliminates any photographer-induced camera motion when the shutter button is pressed. Most modern cameras with a self-timer flash a light during the countdown, emit a beeping sound, or both. These warnings generally increase in speed or intensity during the last few seconds, to warn that the shutter is about to fire. The most common delay is ten seconds. Some cameras also have a two-second and five-second settings. A few cameras provide con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nikon FE
The Nikon FE is an advanced semi-professional level, interchangeable lens, 35 mm film, single-lens reflex (SLR) camera. It was manufactured by Nikon in Japan from 1978 to 1983, and was available new from dealer stock until c. 1984. The FE uses a metal-bladed, vertical-travel focal plane shutter with a speed range of 8 to 1/1000 second, plus Bulb, and flash X-sync of 1/125th second. It had dimensions of height, width, depth and weight. It was available in two colors: black with chrome trim and all black. As on the FM, its model designation did not appear on the front of the camera, but was engraved as a small "FE" preceding the serial number on the rear of the housing. History The FE was the replacement for Nikon EL2 of 1977 and is a member of the classic Nikon compact F-series. It uses a rugged aluminum-copper alloy (duralumin) chassis developed from the one introduced in the Nikon FM in 1977, with minor external controls and cosmetic differences. The Nikon compact F-s ... [...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] |
Tripod (photography)
In photography, a tripod is a portable device used to support, stabilize and elevate a camera, a flash unit, or other videographic or observational/measuring equipment. All photographic tripods have three legs and a mounting head to couple with a camera. The mounting head usually includes a thumbscrew that mates to a female-threaded receptacle on the camera, as well as a mechanism to be able to rotate and tilt the camera when it is mounted on the tripod. Tripod legs are usually made to telescope, in order to save space when not in use. Tripods are usually made from aluminum, carbon fiber, steel, wood or plastic. Usage Tripods are used for both still and motion photography to prevent camera movement. They are necessary when slow-speed exposures are being made, or when lenses of extreme focal length are used, as any camera movement while the shutter is open will produce a blurred image. In the same vein, they reduce camera shake, and thus are instrumental in achieving maxim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rangefinder Camera
A rangefinder camera is a camera fitted with a rangefinder, typically a split-image rangefinder: a range-finding focusing mechanism allowing the photographer to measure the subject distance and take photographs that are in sharp focus. Most varieties of rangefinder show two images of the same subject, one of which moves when a calibrated wheel is turned; when the two images coincide and fuse into one, the distance can be read off the wheel. Older, non-coupled rangefinder cameras display the focusing distance and require the photographer to transfer the value to the lens focus ring; cameras without built-in rangefinders could have an external rangefinder fitted into the accessory shoe. Earlier cameras of this type had separate viewfinder and rangefinder windows; later the rangefinder was incorporated into the viewfinder. More modern designs have rangefinders coupled to the focusing mechanism so that the lens is focused correctly when the rangefinder images fuse; compare with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angénieux Retrofocus
The Angénieux retrofocus photographic lens is a wide-angle lens design that uses an inverted telephoto configuration. The popularity of this lens design made the name retrofocus synonymous with this type of lens. The Angénieux retrofocus for still cameras was introduced in France in 1950 by Pierre Angénieux. Inverted telephoto concept The telephoto lens configuration combines positive and negative lens groups with the positive at the front, so as to reduce the back focal distance of the lens (the distance between the back of the lens and the image plane) to a figure shorter than the focal length. This is for practical, not optical reasons, because it allows telephoto lenses to be made shorter and less cumbersome. The inverted telephoto configuration does the reverse, employing one or more negative lens groups at the front to increase the back focal distance of the lens – possibly to a figure greater than the focal length – in order to allow for additional optical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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