What is the name of the video explaining the camera lens?

Pull ring explains the video of camera lens called pull ring. In fact, the tab is like a seesaw-watch it again and again, rewind it again and again, analyze and record what you see, and sum it up. Watch movies one by one and interpret movies in depth. Then record the content, scene scheduling, mirror mode, scenery, editing, sound, picture, rhythm, performance and seat of each shot, and finally summarize. Read a book a hundred times and you will understand its meaning. So is watching movies. Tab is watching a movie. The improvement of film professionalism needs to be gradually accumulated. To others, the pull ring may be hard and monotonous, but for those who are obsessed with film art, they enjoy it.