数码相机参数

数码相机参数 Digital camera parameters. TXT for too long is probably not what you wanted. A layer of autumn rain is cool, one petals fall off a fragrance, the same year is unforgettable, a kind of leisure worry has nowhere to hide. Happy life nine words: have hope, have work, some people love. A woman and a woman are friends, in the presence of green leaves, but also in the heart of the saffron. In front of the digital camera, you buy a lot of friends asked the first sentence, what is your digital camera pixels, in fact, this is a point, but can not lead to higher pixel comes higher clarity, he can only lead to the higher resolution on the computer! Next, let me understand the secret between CCD and pixels! How many CCD pixels do you need? CCD is the abbreviation for Charge Coupled Device in English, which is called "charge-coupled Device" in Chinese. Functionally, it is responsible for converting the light signals from the camera to electrical signals, similar to those of conventional optical cameras. CCD photoelectric conversion is achieved through a lot of photosensitive points (MOS capacitors) that are covered with CCD. A picture shows the color, brightness, and grayness of the light. Another description of CCD is "pixels". In theory, the more pixels, the more subtle the image will be captured and the more subtle the image will be. In other words, the most direct way to improve the resolution of the image is to increase the number of pixels, the number of points of the CCD. For this reason, the number of CCD pixels is made up Digital camera image quality of a very important decision factors, even by most of the people as the only important parameters, especially in the average consumer, only pixel theory "has become the mainstream consumption idea. In the first example, the colleague, just five megapixels, could tolerate even zoom and nimh batteries. So, in practice, how should we look at the number of pixels? Some people say that if you want to achieve the quality of a regular 35mm optical camera, the digital camera will have to be at least 10 million pixels. The other implication of this is that even if a high-end home digital camera, like 6 megapixels, is not as good as a normal optical camera. But that's not quite the case, the comparison is unfair, because everything depends on our application. In particular industries such as publishing, video, and advertising, they often need to put a lot of pictures. For this kind of application, the current state-of-the-art multipixel digital camera is also less than conventional optical cameras. In the household sector, however, there is very little need to scale up to more than 7 inches -- even a 7 inch photo, and 2 megapixels are fully needed. Here's a list of resolutions, pixels and the actual image size: 600 x 800 = 48m pixels = 3 inches 700 times 1000 = about 800,000 pixels = 5 inches (3.5 by 5 inches, millimeter spec 89 by 127) 800 times 1200 = about 1 megapixels = 6 inches (4 by 6 inches, millimeter spec 102 by 152) 1000 x 1400 = about 1.5 megapixels = 7 inches (5 by 7 inches, millimeter spec, 127 by 178) 1200 * 1600 = approximately 2 megapixels = 8 inches (6 x 8 inches, 215x2203) 1600 by 2000 = about 3.1 megapixels = 10 inches (8 by 10 inches, millimeter spec 203 by 258) 1600 by 2400 = about 4 megapixels = standard photos (8 by 12 inches, millimeter spec 203 by 304) 1600 by 2800 = about 4 megapixels = width (8 by 14 inches, millimeter spec 203 by 356) (note: the above resolution is the resolution of the corresponding size photos need, may be related to the resolution of the digital camera can adjust the grade is a little different. In general, the resolution of the image product is required for the number of pixels. In the same number of cases, the maximum size of an image can be approximately the same. For example, a 3-megapixel product, whose adjustable resolution level may be 2048 by 1536 in a digital camera, may also show a 160-by-2000 performance. ) From the above comparison of the data we can see that for the average family, if there is no special need to enlarge, so, should be a ratio of 3 million pixels are good products, even, also said in the past 2 million pixels. If on a relatively low price, one-sided pursuit of high pixel value, it's most likely losses of other functions, and these functions, such as zoom, macro photography and camera quality, chip processing speed, etc., of digital imaging in terms of quality, also is extremely important. That's why there are some 3 million or even 4 megapixel digital cameras, and the quality of the images is not as good as the 2 megapixel product. One market trend now is that many manufacturers are using the user's blind worship of pixels to play with pixel-upgraded games. The cost of upgrading, of course, is the rapid increase in costs. As ricoh R series, its R5, R3 and R4 compared, in addition to increased to 5 million by 7 million pixels, features almost no other changes, however, is the change of the pixels, will cause the change of the price from 2000 yuan to 3000 yuan, increased by almost 1000 yuan! In order to cater to the user's preference for pixels, some vendors are also working on pixels, such as fushi's SuperCCD technology. And the real thing about interpolating pixels is that you get new pixels through the software, which increases the resolution of the image. As new is not physical photographic point of CCD pixels, which is not true on the image, although the picture can be doubled to increase, but the picture quality will reduce. Therefore, it is important to understand what the value of optical pixels and interpolation pixels are. The size of the neglected CCD If take Canon A610 and A700 both products are put together to compare, we will find that the former is 5 million pixels, while the latter is 600 pixels, but the price is impossible! The reason for this is that, apart from the lens, the size of the CCD area is also an important factor in the quality of digital camera imaging. Canon A610 is 5 megapixels, with a CCD area of 1/1.8; The A700 is 6 megapixels, and the CCD area is only 1/2.5 of an inch -- the pixels are small and the pixels are large. When choosing a digital camera, focus on the CCD pixels consumers may ignore the CCD area - probably the more important parameters, and to understand the size of the CCD is the size of the LCD screen. And some products don't seem to be willing to tell consumers about the size of their CCD. What does the increase of the CCD area mean? In the same pixel condition, the CCD area is different, and it directly determines the difference between the size of the photosensitive point (MOS). Photographic point of function is responsible for photoelectric conversion, and its volume, the greater the able to accommodate the higher the limit value of the charge, the light sensitivity is stronger, the level of the description will be rich. Conversely, if the volume of the light is too small, the charge overflows easily, making the image noise. Not only that, the size of the CCD determines the length of the focal length. The digital camera, which is much smaller than the 35mm film of a conventional optical camera, can be made very short in focal length. If you increase the area of CCD, you will have to bring the focal length of the lens, which naturally increases the cost of production. Likewise, if a CCD smaller, so, in the case of a shorter focal length of the camera, also can make similar to the effect of long, of course, its taking pictures of the depth of field will also be discounted - this is also a household digital camera depth of field with professional camera than an important reason. Based on that, Some digital camera players don't think that just upgrade the number of pixels without changing the size of CCD, they believe that if the same CCD area, might as well buy low pixel values of products. This is true if the data in the tables are reconnected, and the CCD pixels are in a state of waste. For professional digital camera, the CCD area tend to do more, such as the Canon EOS 30 d, the pixels is only 8.2 million, but the price is as high as 10000 yuan, an important reason is that the CCD area up to 22.5 mm x 15 mm. Compared with them, the Canon new A640 at present, although the pixels to 10 million pixels, even more than 30 d Canon, more than 200 pixels, but its CCD area is only 1/1.8 of an inch (8.1 mm x 6.64 mm), far less than 30 d Canon. The ISO value: In both traditional and digital cameras, this is the size of film or CCD. Ordinary household film general ISO value is 100, this as a standard, below this value, we can realize various occasions the correct exposure, basic suggest beginners friends can use this value to operate. If less than 100, such as 50 or less, the picture quality will be improved, the picture is more exquisite, suitable for still life scenes, such as a portrait or landscape level are very abundant. Low sensitivity was the cause of the impact of the sensitive time longer, it will have to use amplification aperture or slow shutter exposure to supplement, in order to achieve the correct picture. If the sensitivity value higher than 100, 200400 or higher, for example, so grainy film images will strengthen, CCD images have noise, its advantage can choose a faster shutter speed or smaller aperture, so that through the narrow into the light to reach the correct exposure. This kind of method is suitable to capture motion picture or motion picture, reasonable use can produce compare special effect. It is also a good idea to raise your sensitivity below the darker environment. Aperture: The amount of the optical lens have aperture control effect, usually the larger the lens aperture (the smaller the F value), through the more light, the characteristics of large aperture bring is able to obtain very shallow depth of field, clear is the main body, the foreground of fuzzy, the effect of this method is often used in portrait photography, can highlight the main body. Of course, the focus of the large aperture must be accurate, otherwise the shallow depth of field will easily be taken as the focus. The smaller the aperture (F value), by the light of the less, longer depth of field can be obtained under the small aperture, which is suitable for show wide landscape and environment, high-resolution range is very large. Shutter: With the change of the aperture, can adjust the shutter speed to achieve the correct exposure, the shutter is the length of exposure time, such as your aperture determined for F8, the faster the shutter, in the light of the less, the slower shutter are more into the light, speeding shutter can instantly condensation on the negatives or CCD, such as gushing waterfalls, condense into glittering and translucent get rid of water droplets in the sun. If you slow down the shutter speed, then the body will be clear, and the background will become a blur of motion, and the image will be enhanced. Blur the effect of motion Aperture and shutter relationship: After a correct exposure to determine when a scene, you can change different exposure to achieve different effects, such as: a scene at ISO100 below of the correct exposure is F8, 1/125, so, you can choose F5.6, 1/250 - F11, 1/60, and so on many kinds of combination, to control the representation of the picture, there is a commonly used photography rule "reciprocal rate" - is to ensure that the correct exposure, can amplify an aperture, a block at the same time improve the shutter, or narrow aperture, slow down the block the shutter at the same time. This is a kind of a kind of a kind of a kind of this kind of this kind of the relation, enlarge or shrink a few aperture, should be accordingly accelerated or slow down a few shutter. In order to keep the total amount of exposure correct, To ensure the quality of the picture, the image is achieved by changing the combination of aperture and shutter. This reciprocal rate, of course, also have failure such as shooting moonlit sky, and so on special environment, here is not a simple reciprocity rate can be solved, rely more on the photographer's experience and skill, it is need to practice to summarize. The use of ISO value: The ISO value can control exposure, usually adding a block of ISO value, the aperture can get a stop, or the shutter gets faster, and vice versa. This also needs to be adjusted according to the requirements of the picture. Of course in the general digital camera, high ISO will lead to higher stability and sensitivity, but it is also the inevitable cause imaging effect is reduced, such as filming in ISO64 and ISO200 shot with a plate, the ISO images is almost certainly to clean than the latter, noise will reduce a lot, so people in the use of general DC, in the condition of the light is not very good, it is recommended to use feet rather than improve the ISO to improve stability.