Video recorded by SLR, close-up, surprisingly big face! How ugly! Face is big, facial features are small. Why?

The imaging principle of camera lens, that is, the imaging principle of convex lens, shows that the closer an object is to the lens, the bigger the image is, and the farther it is, the smaller the image is. However, the closer the object is to twice the focal length of the lens, the greater the imaging perspective relationship of the lens. At this time, the nose of the people near the camera is very big, and the face a little farther away is much smaller and the ears are smaller. This is the characteristic of lens imaging. When using wide-angle end, that is, short focal length, the effect of this large perspective ratio is more obvious. Therefore, when taking portraits in general, try not to take close shots, especially when taking close shots with wide-angle lenses, so as to avoid the phenomenon of distorted and bloated proportions before and after portraits.