I want to ask the photography teachers! Why can't the camera be clearly focused on the car rearview mirror?

I can tell you very clearly that it is ok to shoot the scenery in the rearview mirror from a relative angle, and there is definitely no problem in focusing clearly.

Let me analyze why you can't focus clearly. I guess there are two reasons.

The first reason is the lens. Because of the small space in the car, it is estimated that you are using a telephoto lens and can't focus. This is because your lens is too close to the main picture and beyond the imaging range. In this case, you can't focus, the shutter can't be pressed or the shooting is blurred.

The second reason is that the color of the subject in the mirror is too close to focus. If this is the case, we can turn on the manual focus mode, and we use manual focus.

These are two special situations that I understand can't focus clearly. hope this helps