Digital zoom and Optical zoom

There are two kinds of zoom, one is digital zoom; One is optical zoom.

Digital zoom

Digital zoom, digital zoom is through the processor in the digital camera, the image of each pixel area to increase, so as to achieve the purpose of amplification. This technique is like using image processing software to enlarge the area of the image, but the program is carried out in the digital camera. Part of the pixels on the original CCD image sensor are enlarged by "interpolation" processing method, and the pixels on the CCD image sensor are enlarged by interpolation algorithm to the whole picture.

Optical zoom

Optical Zoom, or Zoom, is a digital camera that relies on the structure of the Optical lens. The optical zoom mode of digital camera is similar to that of traditional 35mm camera, that is, the lens is moved to zoom in and out of the scene to be photographed. The larger the optical zoom, the farther the scene can be photographed. Optical zoom is produced by changing the position of the lens, the object and the focus. When the image plane moves in the horizontal direction, as shown in the figure below, the vision and focal length will change, and further scenery will become clearer, making people feel like objects progressing.

Obviously, there must be two ways to change the Angle of view. One is to change the focus of the lens. In photographic terms, this is optical zoom. To change the focal length of a zoom lens by changing the relative position of the lenses. The other is to change the size of the imaging surface, the diagonal length of the imaging surface, which in today's digital photography is called digital zoom.

shoot

The scientific name of continuous shooting function is Continuous shooting, which saves the time of data transmission to capture the shooting time. By loading the data into the digital camera's internal high speed storage (cache), rather than transferring data to the memory card, continuous shooting mode can take multiple photos in a short time. Since digital camera needs to go through photoelectric conversion, A/D conversion and media recording, etc., both conversion and recording need time, especially more time.

Automatic white balance

The English name of White Balance is White Balance. The color of the object will be changed by the color of the light it casts, and the photos taken in different light situations will have different color temperatures. For example, a photo taken with a tungsten light bulb might be yellow. Generally speaking, CCDS have no way to automatically correct for light changes like the human eye does. White balance means that no matter what the ambient light is, having a digital camera default to "white" means that it can recognize white and balance other colors against colored light.