Several common misunderstandings when buying digital cameras[Copy link]
[][]Several major misunderstandings when buying digital cameras High pixels equal high-quality photos? Many users who buy digital cameras for the first time will consider pixels as the primary factor. In their opinion, pixels are the basis for judging the quality of digital cameras. It seems that digital cameras with high pixels will inevitably get high-quality shooting effects. In fact, the relationship between pixels and quality is far from being as simple as a direct ratio. The first thing to be sure of is that pixels do not determine quality. There are many factors that affect the quality of digital cameras. Among them, the factor that can directly affect the image quality is the lens. Whether it is an optical camera or a digital camera, the lens is one of the most important factors that cannot be ignored. Ordinary digital cameras use CCD for photosensitivity, and its area is much smaller than that of traditional film. This places more stringent requirements on the resolution of the lens. Otherwise, even with a high number of pixels, the image quality will still be poor due to the lens. In other words, the resolution ability of the optical lens used in digital cameras must be better than the resolution of the CCD, so choosing a digital camera with a high-quality lens is much more important than simply looking at pixels. A clean picture with low noise is always accompanied by high resolution? Noise is the enemy of digital camera imaging quality. Most users tend to think that a clean picture with low noise always means a high-resolution photo. In fact, for digital cameras, the situation is not that simple. Since the types of image sensors in digital cameras are very simple, they are CCD or CMOS, which means that the signals of each other's image engines are relatively close. However, the post-processing of image data creates differences in styles between different brands and different series of models, which is the embodiment of the core technology of each manufacturer, especially the research and development of noise reduction technology has a great impact on the resolution. The higher the ISO, the greater the noise? Slightly experienced digital camera users sometimes use high sensitivity settings when shooting moving objects or shooting in dark environments. When shooting at a high ISO value, the shutter speed is faster and it is easier to shoot, but a problem brought by high sensitivity is that the noise of the picture will increase. In fact, this is a dilemma that many digital camera users are quite headache. Low sensitivity means that shooting is not easy and there are fewer noise points. High sensitivity means that shooting is easy and there are more noise points. Generally speaking, we have to reduce the resolution of photos taken with high sensitivity to appreciate them, and the noise on the photos is not so obvious at this time. A simple analysis is that this is because a pixel on the image after reduction is obtained by merging multiple original pixels. In other words, three noise points are turned into one noise point. This is not a very strict explanation, but it can help us understand this phenomenon. Each camera has the best effect according to the number of pixels when shooting at high sensitivity settings. This requires the user's actual experience. Let's make an analogy. If they are all set at ISO400, the shooting noise of a 2-megapixel digital camera at a resolution of 640×480 may be the smallest, while a 5-megapixel digital camera at a resolution of 1024×768 can achieve good results. The higher the number of CCD pixels, the faster the focusing speed can be? Let's take a look at the earlier digital cameras first. Because ordinary digital cameras must read CCD imaging signals when focusing, focusing and response speed used to be the eternal pain in the hearts of the first generation of high-pixel digital cameras. The increase in pixels means that the amount of data for each CCD signal reading will also increase, and subsequent processing such as focusing, metering, and LCD screen display will also be burdened. Therefore, we often see that in the digital camera series based on the same hardware platform, the speed of low-pixel products is often higher than that of the "big brother" with high pixel counts. Lithium batteries have high energy density and compact size. Are they the first choice for powering digital cameras? We first need to understand what are the big power consumers in digital cameras. The LCD screen, flash, image sensor, and processing engine are all big power consumers, and they are basically burst-type. They only need a large current at the moment of work, and the static current is very small at ordinary times. This determines the power consumption characteristics of digital cameras, and the power supply needs to have the ability to supply large currents in a sudden manner. From this point of view, batteries with relatively low internal resistance are more suitable for digital cameras, which can significantly improve the response speed of digital cameras. From the analysis of the average charging time of the flash, cameras using lithium batteries are far ahead, usually only 3 seconds, while models using nickel-metal hydride batteries are often longer than 6 seconds. But in terms of capacity, lithium batteries no longer have obvious advantages. Since 2003, NiMH batteries with a capacity of more than 2000mAh have been continuously introduced, while the capacity of lithium batteries in ordinary digital cameras is often around 1000mAh. Moreover, digital cameras that use universal NiMH batteries can always buy emergency batteries or use other people's chargers to charge at any time, and rarely encounter embarrassing situations due to battery exhaustion. Using a dedicated charger, the charging time is often reduced to less than 4 hours, catching up with lithium batteries. The abundant energy and nearly 1000 charge and discharge life of NiMH batteries make it the most cost-effective digital camera battery at present. [] In addition, the voltage of the battery is also an issue worthy of attention. Recently, more and more digital cameras use two No. 5 batteries. Reducing weight and energy consumption is certainly a good thing, but on the same type of hardware platform, high power supply voltage can often bring faster shooting and processing speeds, as well as higher image signal-to-noise ratio. The 12V NP-E3 NiMH battery pack used in the EOS-1D/1Ds series is a good example. Therefore, using high-voltage battery packs on high-performance digital cameras may still be an inevitable choice for some time.
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