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Viewfinders International Film Festival For Youth
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, be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nikon D90 Viewfinder
(, ; ), also known just as Nikon, is a Japanese multinational corporation headquartered in Tokyo, Japan, specializing in optics and imaging products. The companies held by Nikon form the Nikon Group. Nikon's products include cameras, camera lenses, binoculars, microscopes, ophthalmic lenses, measurement instruments, rifle scopes, spotting scopes, and the steppers used in the photolithography steps of semiconductor fabrication, of which it is the world's second largest manufacturer. The company is the eighth-largest chip equipment maker as reported in 2017. Also, it has diversified into new areas like 3D printing and regenerative medicine to compensate for the shrinking digital camera market. Among Nikon's many notable product lines are Nikkor imaging lenses (for F-mount cameras, large format photography, photographic enlargers, and other applications), the Nikon F-series of 35 mm film SLR cameras, the Nikon D-series of digital SLR cameras, the Nikon Z-series of digital mirro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rolleicord
The Rolleicord is a medium-format twin lens reflex camera made by Franke & Heidecke (Rollei) between 1933 and 1976. It was a simpler, less expensive version of the high-end Rolleiflex TLR, aimed at amateur photographers who wanted a high-quality camera but could not afford the expensive Rolleiflex. Several models of Rolleicord were made; the later models generally had more advanced features and tend to be valued higher in today's market. The first Rolleicord, introduced in November 1933, was the Rolleicord I. This camera was a simplified version of the Standard Rolleiflex, with a cheaper 75mm Zeiss Triotar lens and a simplified film advance mechanism using a knob instead of the crank found on the Rolleiflex. The Rolleicord I was available either with a plain leatherette covering or elaborately patterned metal faceplates. The latter variant is referred to as the "Art Deco" Rolleicord. The models that have the letters DRP on the left and to the right DRGM on the front of the camera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
On-screen Display
An on-screen display (OSD) is an image superimposed on a screen picture, commonly used by modern television sets, VCRs, and DVD players to display information such as volume, channel, and time. History In the past, most adjustments on TV sets were performed with analog controls such as potentiometers and switches. This was used more recently also in monochrome portable TVs. After remote controls were invented, digital adjustments became common. They needed an external display, which was LED, LCD, or VFD based. Including this display increased manufacturing costs. When electronics became more advanced, it became clear that adding some extra devices for an OSD was cheaper than adding a second display device. TV screens had become much bigger and could display much more information than a small second display. OSDs display graphical information superimposed over the picture, which is done by synchronizing the reading from OSD video memory with the TV signal. Some of the first O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Light-emitting Diode
An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current. This organic layer is situated between two electrodes; typically, at least one of these electrodes is transparent. OLEDs are used to create digital displays in devices such as television screens, computer monitors, and portable systems such as smartphones and handheld game consoles. A major area of research is the development of white OLED devices for use in solid-state lighting applications. There are two main families of OLED: those based on small molecules and those employing polymers. Adding mobile ions to an OLED creates a light-emitting electrochemical cell (LEC) which has a slightly different mode of operation. An OLED display can be driven with a passive-matrix (PMOLED) or active-matrix (AMOLED) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Crystal Display
A liquid-crystal display (LCD) is a flat panel display, flat-panel display or other Electro-optic modulator, electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly but instead use a backlight or reflector (photography), reflector to produce images in color or monochrome monitor, monochrome. LCDs are available to display arbitrary images (as in a general-purpose computer display) or fixed images with low information content, which can be displayed or hidden. For instance: preset words, digits, and seven-segment displays, as in a digital clock, are all good examples of devices with these displays. They use the same basic technology, except that arbitrary images are made from a matrix of small pixels, while other displays have larger elements. LCDs can either be normally on (positive) or off (negative), depending on the polarizer arrangement. For example, a character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode Ray Tube
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms ( oscilloscope), pictures (television set, computer monitor), radar targets, or other phenomena. A CRT on a television set is commonly called a picture tube. CRTs have also been used as memory devices, in which case the screen is not intended to be visible to an observer. The term ''cathode ray'' was used to describe electron beams when they were first discovered, before it was understood that what was emitted from the cathode was a beam of electrons. In CRT television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster. In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, green, and bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Viewfinder
An electronic viewfinder (EVF) is a camera viewfinder where the image captured by the lens is displayed on a small screen (usually LCD or OLED) which the photographer can look through when composing their shot. It differs from a live preview screen in being smaller and shaded from ambient light, and may also use less power. The sensor records the view through the lens, the view is processed, and finally projected on a miniature display which is viewable through the eyepiece. Digital viewfinders are used in digital still cameras and in video cameras. Some cameras (such as Panasonic, Sony, Fujifilm) have an automatic eye sensor which switches the display from screen to EVF when the viewfinder is near the eye. More modest cameras use a button to switch the display. Some have no button at all. While many cameras come with a built-in EVF, this is fixed in place and can only be used while holding the camera to the user's eye, which may not be convenient. Other cameras don't come with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optics
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Because light is an electromagnetic wave, other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties. Most optical phenomena can be accounted for by using the classical electromagnetic description of light. Complete electromagnetic descriptions of light are, however, often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these, geometric optics, treats light as a collection of rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive model of light, which includes wave effects such as diffraction and interference that cannot be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescope
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects, the word ''telescope'' now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors. The first known practical telescopes were refracting telescopes with glass lenses and were invented in the Netherlands at the beginning of the 17th century. They were used for both terrestrial applications and astronomy. The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope. In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. Etymology The word ''telescope'' was coin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Viewfinder
An electronic viewfinder (EVF) is a camera viewfinder where the image captured by the lens is displayed on a small screen (usually LCD or OLED) which the photographer can look through when composing their shot. It differs from a live preview screen in being smaller and shaded from ambient light, and may also use less power. The sensor records the view through the lens, the view is processed, and finally projected on a miniature display which is viewable through the eyepiece. Digital viewfinders are used in digital still cameras and in video cameras. Some cameras (such as Panasonic, Sony, Fujifilm) have an automatic eye sensor which switches the display from screen to EVF when the viewfinder is near the eye. More modest cameras use a button to switch the display. Some have no button at all. While many cameras come with a built-in EVF, this is fixed in place and can only be used while holding the camera to the user's eye, which may not be convenient. Other cameras don't come with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Because light is an electromagnetic wave, other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties. Most optical phenomena can be accounted for by using the classical electromagnetic description of light. Complete electromagnetic descriptions of light are, however, often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these, geometric optics, treats light as a collection of rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive model of light, which includes wave effects such as diffraction and interference that cannot be ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Live Preview
Live preview is a feature that allows a digital camera's display screen to be used as a viewfinder. This provides a means of previewing framing and other exposure before taking the photograph. In most such cameras, the preview is generated by means of continuously and directly projecting the image formed by the lens onto the main image sensor. This in turn feeds the electronic screen with the live preview image. The electronic screen can be either a liquid crystal display (LCD) or an electronic viewfinder (EVF). Background The concept for cameras with live preview largely derives from electronic (video) TV cameras. Until 1995 most digital cameras did not have live preview, and it was more than ten years after this that the higher end digital single-lens reflex cameras (DSLR) adopted this feature, as it is fundamentally incompatible with the swinging-mirror single-lens reflex mechanism. The first digital still camera with an LCD for autogain framing live preview was the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
