Why does the TV camera shoot 25 frames per second?

Our country uses Pal system, resulting in only 25 frames per second.

The TV is also pal's, of course, it's 25 frames.

The reason for the flicker is that the scanning frequency of the camera is lower than that of the TV. It can be solved by adjusting the electronic shutter of the camera.

Numbers? SD of 25 frames per second. There are 25, 30 and so on in HD.

You can refer to my Baidu space for details. Do you have the contents of this room?