When filming, there are often pictures of the protagonist looking in the mirror. How can we avoid the photographer not appearing in the camera?

The problem you mentioned is generally called "laziness".

The actual situation is more serious. In addition to the cameraman, there are also lighting engineers, field workers and other auxiliary work, so there are many people and equipment. Around the actors.

Playing around is a taboo in film shooting, so this situation is taken into account in lens design.

Even shooting at a small angle will not have this problem.

The main solutions are "scene control" and "lens focus control"

The shots in the mirror are all small scenes, close-ups, close-ups.

This only intercepts a part of the picture, and other parts are difficult to show.

In addition, "telephoto shooting" is adopted, so the camera can shoot at a far place, so that it will not enter the painting.

Here is a working photo of TV series shooting, for your reference.