What are the meanings of "W" and "T" in camera zoom?

W and t respectively represent two boundaries of zoom capability. W comes from the abbreviation of Wide, which means wide angle. Represents the camera's wide-angle capability, that is, how wide the camera can shoot. T comes from the abbreviation of Tele, which means telephoto. Represents the telephoto ability of the camera, that is, how far the camera can shoot the picture. At present, this can only be seen in the camera that comes with the mobile phone. SLR cameras don't, because the zoom of SLR cameras is not through the body, but through the lens, and not all lenses have zoom and fixed focus lenses.

The principle of optical zoom

Optical zoom is achieved by changing the positions of lens, object and focus. When the image plane moves in the horizontal direction, the visual angle and focal length will change, and the farther scenery will become clearer, making people feel that the object is moving forward. Obviously, there are two ways to change the perspective. One is to change the focal length of the lens. In photography, this is optical zoom.

The focal length of the zoom lens is changed by changing the relative position of the lens. The other is to change the size of the imaging plane, that is, the diagonal length of the imaging plane. In digital photography, this is called digital zoom. In fact, digital zoom does not change the focal length of the lens, but changes the viewing angle by changing the diagonal of the imaging plane, thus producing an effect equivalent to the focal length change of the lens.

digital zoom

DigitalZoom, called digital zoom in English, enlarges the area of each pixel in a picture through the processor in a digital camera, so as to achieve the purpose of enlargement. This technology is like enlarging the area of a picture with image processing software, but the program is executed in a digital camera. Some pixels on the original CCD image sensor are enlarged by interpolation, and the pixels on the CCD image sensor are enlarged to the whole picture by interpolation algorithm. In fact, digital zoom does not change the focal length of the lens.

principle

Use software to judge the color around the existing pixels, and insert the pixels added by special algorithm according to the surrounding color.

The total zoom number of a digital camera is calculated as follows: For example, the optical zoom of Sony F7 17 is 5 times, while the digital zoom is 2 times, so the maximum zoom number is 10 times. Digital zoom in digital cameras can usually be turned off. In addition, there is a brand-new and unique Sony intelligent zoom function, which can enlarge the zoom shooting without enlarging the particles, so that the enlarged image can maintain the original detail quality. Intelligent zoom provides different degrees of enhanced zoom function according to the choice of different image sizes. Unlike digital zoom, smart zoom can maintain the same image quality as the original image.