Should the ID camera be parallel to the person's face?

a photo with the most practical use in life, it is a basic requirement that the photo camera should be parallel to the front of a person's face, mainly for the following reasons:

1. The photo should correctly reflect the characteristics of a person's face, and it must be taken from a perspective parallel to the front

2. Looking up or looking down is not true in perspective, so it is impossible to get a correct impression of the front

3. Although the side shooting is parallel, it is It is impossible to predict the correct frontal appearance from the side

4. The ID photo is a recognition map of human face in two-dimensional space, and other shooting methods are not as rich as the information provided by the frontal face. The frontal parallelism is the angle that can best reflect the facial features in the two-dimensional map.