This term is the physical size of the camera's sensor. It is given as a ratio. Most digicams today are using 1/2.5 sensors. This translates to a 0.4 inches.
2006-08-20 02:44:22
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answer #1
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answered by fredshelp 5
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The digital sensor element is equivalent to negative film in analog camera's. It is pretty small in all consumer digicams - typically around the size of a fingernail (and a small fingernail at that!).
Most of the current small 5MP digital cameras use 1/1.8" sensors which are about 7mm x 5mm. They have an area 25x smaller than 35mm film and about 9.5x smaller than a small sensor digital SLR like the Canon EOS 10D. You might wonder why sensor size matters and that's a pretty complex issue. The bottom line is that, for a given pixel count, the larger the sensor (and hence the larger the area of the individual pixels) the better the image quality and the lower the noise level. While large sensor cameras like the EOS 5D can operate at the equivalent of ISO 6400 (though the image does get noisy), many consumer digicams with small sensors cannot operate above ISO 400 or 800 before the noise becomes excessive.
Another factor in quality here is that small sensors tend to be of a different type than large sensors. Small sensors, and the sensors used on all consumer digital cameras, use a scheme which can read the data from the sensor in real time using a scheme called "interline transfer" and the CCD electronics control exposure rather than a mechanical shutter. Large sensors used on more expensive Digital SLRs are often of a different design known as full frame - which doesn't refer to their size, but their design - and which require the use of a mechanical shutter. They don't read out and the display the data in real time, only after the exposure so they can't give real time LCD displays or record video. The advantage of this scheme is that the whole pixel area can be used to capture light while interline transfer CCDs use part of each pixels to store charge. Since smaller pixel areas generate more noise and interline transfer CCDs are not only smaller to start with but use some of their pixel area for charge storage, their noise level is significantly higher. So the smaller interline transfer sensors in consumer digital cameras yield lower quality images than those used in higher end DSLRs, they can do more "tricks" like recording video clips and giving a live image display on their LCD screen. The lack of a mechanical shutter also makes the cameras cheaper and simplifies construction.
2006-08-20 03:15:28
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answer #2
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answered by Ric 1
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A extreme pixel density isn't reliable, so a small sensor with distinctive pixels could have greater noise and not carry out as nicely as a much better sensor with the comparable quantity of pixels or an identical sized sensor with fewer pixels in low easy. Funnily sufficient it got here up in our club basically final night we took the comparable portrait shot of a manikins head (below low lights (a million X 100W lamp) to truly try them) with 3 factor and shoots then printed at A3 on a calibrated device. the final by utilising far replaced into my previous Olympus C2000 (2.1Mp), the 2nd replaced right into a 4Mp Fuji and the worst (rather) replaced into my new Canon G10, 14Mp on a much better sensor than the different 2 (which gave ineffective effects). The Olympus replaced into in all threat helped by utilising its f2.8 lens. We ran the try back with plenty greater helpful lights (2 X 500W lamps) and the outcomes reversed. each and each of the DSLR's we examined Canon, Nikon, Pentax and a Sony Alpha all with 10Mp(ish) sensors all gave continuously reliable effects below the two circumstances. seems to proove something. Chris
2016-12-17 14:00:31
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answer #3
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answered by Anonymous
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It's usually a 1/3 CCD (charged coupled device) chip.
2006-08-20 04:00:38
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answer #4
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answered by Anonymous
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