Why is the face of the rear camera crooked?

The face taken by the rear camera is crooked, because the rear camera of the mobile phone usually takes a distant view. The software will be optimized by perspective principle. If the software can't recognize the scene when shooting a portrait at close range, it will optimize it according to the distant scene, thus making the face look a little distorted. If you take a close-up face, it is generally better to use a front camera. In addition, I found that my face was crooked and my teeth were crooked after taking pictures. It is recommended to go to the dentist for relevant examination. If the teeth are not straight, I can choose to correct them.