词条 | digital camera |
释义 | digital camera photography ![]() Unlike film cameras, digital cameras do not have any mechanical parts (shutters) or chemical agents (film) and rarely have a viewfinder, which is typically replaced by a liquid crystal display (LCD). At the core of a digital camera is a semiconductor device, such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), which measures light intensity and colour (using different filters) transmitted through the camera's lenses. When light strikes the individual light receptors, or pixels, on the semiconductor, an electric current is induced and is translated into binary digits for storage within another digital medium, such as flash memory (semiconductor devices that do not need power to retain memory). Digital cameras are commonly marketed by their resolution in megapixels (millions of pixels)—for example, a 2.1-megapixel camera has a resolution of 1,600 by 1,200 pixels (the “missing” megapixels are used for an analog-to-digital converter, or ADC). Kodak developed the first megapixel camera in 1986; it could produce a film-quality 5×7-inch (12.5 ×17.5-cm) print. |
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