The benefits of digital cameras

Digital camera is a kind of camera that uses electronic sensors to convert optical images into electronic data, which is different from traditional cameras to record images through chemical changes on the negative caused by light. The word "Digital" was originally a Hong Kong translation of English digital, and was later introduced to the mainland. According to the difference of function, structure and image quality, the common digital cameras can be divided into four types: consumer digital cameras (commonly known as fool cameras), monocular digital cameras, digital SLR cameras and mirrorless interchangeable lens cameras. In addition, there is a digital medium film (120 film) camera specially designed for extremely professional special needs. In digital cameras, photosensitive charge coupled devices or complementary metal oxide semiconductor sensors are used to replace the chemical sensing function of traditional camera negatives. The captured image data is encoded by an integrated microprocessor through a certain algorithm and stored in a digital storage device (memory card, micro hard disk, floppy disk or rewritable optical disk) inside the camera. With the large increase of flash memory capacity and the decrease of price, most digital cameras adopt flash memory as a storage scheme. Digital cameras are rapidly popularized in a short time because of their small size, portability, instant shooting, low cost and convenience for photo storage, sharing and post-editing. Most digital cameras have recording and video recording functions. In 2009, more than 900 million digital cameras (including mobile phones with digital camera functions) were sold worldwide, while traditional cameras have almost disappeared from the market. At present, more and more devices, such as mobile phones, personal digital assistants, personal computers, terminals and tablet computers, also integrate digital camera functions. Consumer digital camera "fool camera" is characterized by its compactness, portability, simple operation and low price. After choosing the built-in shooting mode, you usually just need to press the shutter and get a photo through simple zooming and composition. Adjust the focal length. Because the shooting parameters are almost completely determined by the camera's automatic judgment, it is difficult to operate and the quality is not good when used in non-universal scenes. The monocular digital camera improves the internal hardware and lens group of the camera, and adds more control buttons to realize the shooting operability close to the digital monocular mirror, and adopts PASM manual control. Because the lens can't be replaced, these products are based on high magnification telephoto lens group or large aperture lens group covering multi-focal segments. Digital SLR mirror has strong function, good photo quality and replaceable lens. Within the scope permitted by hardware, the shutter and aperture can be adjusted freely. Manual focusing is supported, and autofocus allows you to select the focus and switch between single shot and continuous shooting mode. The monocular camera is named for its monocular reflective optical viewfinder. However, at present, besides the optical viewfinder (OVF) which relies on the reflective pentaprism group, there is also an electronic viewfinder (EVF) which uses the circuit to transmit images. According to the image sensor area, these cameras can be divided into Quan Huafu (36X24mm) and APS-C size (2 1X 14 to 24X 16).

1/4 tablet (17.3x 13 to 18.7x 14)

Miniature quarter-frame camera, consumer frame and mobile phone frame. The sensitivity of the sensor is doubled, and the aperture diameter is reduced to 1.4/ 1, which is equivalent to doubling the sensor area to improve the focal plane definition. Features The advantages of digital photography over traditional film photography include: compared with traditional photos, printing and mailing. Digital photos can be shared and transmitted quickly and conveniently through the network. Although the memory card of a digital camera is more expensive than the negative, its capacity is larger (2G memory card can take about 100~ 1000 photos according to the set resolution. By 20 10, the price of memory cards is already very cheap, and 2G memory cards are almost as expensive as negatives, and they can be reused. Take pictures immediately, and digital photography can enjoy pictures immediately through the camera. If you are not satisfied, take another photo immediately. Traditional photography often needs to develop the film, and then mistakes such as overexposure, underexposure or jitter will be found. The photoelectric conversion chip can provide a variety of sensitivity options, and the sensitivity can be changed by adjusting the camera settings. Traditional cameras fix the sensitivity according to the film used. With the popularity of home personal computers and the diversification of data storage methods, digital photos can be easily backed up to erasable CDs, hard disks and even online servers. Reduce the risk of losing multiple backups. And digital photos will not turn yellow because of age. After the photos are input into the computer and backed up, they can be rotated, cut, adjusted and compared by editing software. If you are not satisfied, you can restore it through backup and make it again. Traditional negatives need darkroom technology for post-production, but the post-production failed and the negatives could not be recovered. Looking at photos through a computer monitor is much larger than traditional general photographic paper. With the development and popularization of inkjet printer technology, users can print photos comparable to traditional development at home. With the introduction of digital cameras with100000 pixels or more by manufacturers, the imaging quality of digital cameras has its own advantages and disadvantages compared with the traditional 35mm film cameras. Only by outputting large-format works can we find the shortcomings of digital cameras. So only a few professional photographers and movie lovers still insist on using film cameras. Because the image quality of the latest digital single-mirror reflectors from Nikon, Canon and other manufacturers has been further improved, and the post-processing time of these digital products is shorter, and the demand for consumables is less (saving the trouble of carrying and buying a large number of negatives), which is a great temptation for photographers who pay great attention to the timeliness of their works. Usually, with the optical quality of digital SLR cameras, the image of CCD with more than10 million pixels can meet the needs of newspapers or magazines. Journalists don't need to send negatives or developed photos back to the company in person, just send them online. Therefore, at present, digital SLR has replaced the traditional cameras used in most media publishing industries.

Digital camera A Digital camera is a kind of camera that uses electronic sensors to convert optical images into electronic data. Different from the principle that ordinary cameras record images through the chemical changes of silver bromide on film, the sensors of digital cameras are photosensitive charge coupled devices (CCD) or complementary metal oxide semiconductors (CMOS). Images are usually stored in digital storage devices before being transmitted to computers. According to different functions, digital cameras are divided into consumer digital cameras (commonly known as fool digital cameras), digital SLR cameras and digital SLR cameras. The development of digital cameras is a long road. From the end of 1970 to the beginning of 1980s, Kodak Lab produced more than 1000 patents related to digital cameras, which laid the foundation for the current architecture and development of digital cameras, and made digital cameras move towards display step by step. 199 1 year, Kodak finally launched the first commercial digital camera. Nowadays, most consumer digital cameras tend to be portable. The ultra-thin and fashionable design, compact shape and relatively light body have become a major feature of this kind of cameras, so they are also called card machine or DC machine. Consumer digital cameras can be carried around without being bulky; Put them in the pocket of a suit on formal occasions, which will not deform the coat; On other occasions, you can also put the camera in your trouser pocket or hang it around your neck. Consumer digital cameras are fashionable in appearance, large in LCD screen, slim in body and easy to operate. However, the large LCD screen consumes a lot of power and the lens performance is poor. Advantages: 1 Compared with the traditional photo development and mailing. Digital photos can be shared and transmitted quickly and conveniently through the network. Card machine digital camera II. Although the memory card of a digital camera is more expensive than the negative, it has a larger capacity and can be reused. 3. Take photos immediately. Digital photography can enjoy pictures immediately through the camera. If you are not satisfied, take another photo immediately. Traditional photography often needs to develop the film, and then mistakes such as overexposure, underexposure or jitter will be found. 4. The photoelectric conversion chip can provide a variety of sensitivity options, and the sensitivity can be changed by adjusting the camera settings. Traditional cameras fix the sensitivity according to the film used. 5. Personal computers at home are popular, and data storage methods are diverse. Digital photos can be easily backed up to erasable CDs, hard disks and even network servers. Reduce the risk of losing multiple backups. And digital photos will not turn yellow because of age. 6. After the photos are input into the computer and backed up, you can use editing software for post-production, such as rotation, cutting, adjustment and comparison. If they are not satisfied, they can restore it through backup and make it again. Traditional negatives need darkroom technology for post-production, but the post-production failed and the negatives could not be recovered. 7. Looking at photos through a computer monitor is much larger than traditional general photographic paper. Pixel pixels, as one of the standards to measure the quality of digital cameras, are often regarded by consumers as the focus of investigation when purchasing digital cameras. Therefore, many consumers have gone into the misunderstanding of high pixels, blindly pursuing high pixels and taking pixels as the only standard to measure the quality of digital cameras. Digital cameras use CCD or CMOS to sense light, and the number of pixels for shooting images depends on the number of photosensitive units on the CCD or CMOS chip in the camera. Theoretically, the more photosensitive units there are, the clearer the image will be. However, because the photosensitive element area of digital camera is much smaller than that of traditional film, adding too many photosensitive units on the limited chip area will cause many problems, such as the reduction of image signal-to-noise ratio and sensitivity. As we all know, digital cameras need to rely on the internal image processing engine to reduce color errors. The imaging principle of digital camera is essentially different from that of traditional camera. The data obtained by photosensitive elements must be processed and combined to generate the final image file, and the calculation method of processing engine directly affects the quality of the final image. Therefore, pixels can indeed be used as one of the important standards to judge the level of digital cameras, but it is not the only standard. We need to comprehensively examine the quality of digital cameras through their comprehensive indicators. Lens can be said to be the soul of a camera, and digital cameras are no exception. Whether it is an optical camera or a digital camera, the lens is one of the most important elements. In addition, the lens materials of digital cameras are divided into glass and plastic. Some manufacturers emphasize that their camera lens is made of glass, so it has good transparency and the projected image is clearer. But in fact, glass lenses may not bring clearer images than plastic lenses, and glass lenses may also increase the weight of the camera, so we should consider it from many aspects when purchasing, and we should not be limited to this. Zoom function When purchasing a digital camera, the zoom multiple is the focus of consumers' general attention. A larger zoom factor can make a digital camera more flexible, but it is not easy to know the shooting situation of a digital camera just by looking at the size. Zoom is divided into optical zoom and digital zoom. First of all, pay special attention to the range of optical zoom. The smaller the minimum focal length of the camera, the larger the wide-angle shooting range, which is beneficial to shooting large scenes, while the larger the maximum focal length, the stronger the telephoto ability. In addition, unlike traditional cameras, digital cameras also provide digital zoom function, which is very different from optical zoom. Digital zoom is to enlarge the photo taken and then fill in the blank scientifically, which is called interpolation amplification. It should be noted that the more interpolation components, the more details of the sacrificed picture, and the lower the definition. Therefore, the general digital zoom does not have much practical significance. Therefore, when purchasing digital cameras, we should focus on the optical zoom range. Don't listen to the irresponsible propaganda of the merchants, and mistakenly think that the digital zoom function can make up for the lack of optical zoom range.

Reference: Wikipedia