Popularize knowledge of camera lens parameters

The knowledge of camera lens parameters is popularized as follows:

First, pay attention to the image processor.

Many people don't understand how pictures are presented. Actually, it's the image processor. It is responsible for all the operations and operation instructions of the camera at work. The quality of the image processor also determines the quality of the image to a certain extent, especially the JPG format photos, as well as the performance of high sensitivity and internal noise reduction.

Second, pay attention to the focusing system.

Even if you are not proficient in photography, you should know the importance of focusing. If you don't focus well, you can't highlight the key points. When choosing, the key depends on the coverage area and accuracy of the focus, such as the number and layout of cross and double cross focus. Another key parameter is the corresponding aperture. For example, we often see that a sentence describing the center focus is "double cross autofocus, and the center corresponds to f/2.8", which can be interpreted as: when using the aperture of f/2.8 and above, the camera center will start double cross induction; When the aperture less than f/2.8 is used, only the single cross-line sensing is used at the center point.

Third, pay attention to the sensor area.

The area of the sensor is an important factor to determine the imaging quality. If the sensor area is large, the amount of information collected at the same time per pixel is large, and the imaging quality is naturally better than that of the sensor with smaller area. Of course, this is definitely because there are many factors that affect the image quality. We should remember that the larger the sensor area, the better the image quality.

Fourth, understand the camera lens parameters and pay attention to continuous shooting speed.

Of course, the sooner the better, but pay special attention to the continuous shooting parameter. For example, a camera claims that the continuous shooting speed can reach 7 frames per second, and the next line of fine print reads: RAW format is about 15 frames (about 16 frames), and RAW+JPEG: about 8 frames. In other words, if the RAW format is selected, continuous shooting only supports 2 seconds, and then the camera will enter the storage state.

So what is the significance of such a high-speed continuous shooting? When viewing continuous shooting parameters, be sure to pay attention to the number of continuous shooting storage sheets in different formats. Mirrorless cameras often plays this word game. For example, Olympus flagship mirrorless camera E-M 1 has a continuous shooting speed of 1 1 frame per second and a storage capacity of 4 1 frame at the flagship level. However, this is based on single focusing. When continuous shooting focusing is turned on, its continuous shooting speed will drop to about 6.5 frames per second.

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Besides the focal length, the maximum aperture is also a very important parameter. Generally, a fixed-focus lens can reach a larger aperture f/ 1.8 and f/ 1.4. Top zoom heads are generally constant f/2.8, and commonly used middle-priced zoom heads are floating apertures, such as 70-300mm f/3.5-5.6. This actually means that the maximum aperture at the 70mm end is f/3.5 and the maximum aperture at the 300mm end is f/5.6. A large aperture will bring more light, and the depth of field will be shallower and more blurred.