“Yes, and then,” Mary will say to John, “they turn the camera back and expose the other side of the film while he's playing the other part.”
And there you are. All very simple. Easiest thing in the world to explain. But in the meantime Mary and John have lost track of the story, the illusion has been smashed for them and for all the people sitting around them.
Therefore having proven that it is a bad thing to give away the secrets of the director and cameraman and cutter, I will now set down two or three other secrets of the director and the cameraman and the cutter so that other illusions of yours may be spoiled when you go to the theatre. Consequently, if you desire to retain your illusions refrain from finishing this chapter.
The fight on the edge of a high precipice waged between the hero and the villain of the story is a favorite scene of every director's. It is usually terminated when the hero mustering all his strength, lands on the jaw of the villain and tumbles him off the precipice into the nothingness below.
Now, of course villains are expensive commodities, often calling for five hundred dollars a week and more and no director can afford to let one drop over a cliff now and then just for the sake of a thrill. Furthermore, they are usually happily married with large families and these families would be inclined to feel some venom for the director if he permitted the villains to go over the precipices.
So the following course is decided upon as the next best thing to actually killing the villain. The first part of the rough and tumble fight is gone through in a natural way. Then comes the scene which begins with the hero's rush for the villain and ends with the blow that sends the unfortunate over the cliff. The villain takes his nerve with him and stands on the edge of the cliff and leans as far back as he is able. The hero then places one fist on the villain's jaw and allows it to rest there lightly. Then he pulls it back suddenly. The villain follows him back to safety and they proceed to fight in a rough and tumble way again.
But what has the camera been doing all the time? Ah, the camera has been grinding backwards so that when the above scene is flashed on the screen it looks as if the hero really hit the villain on the jaw. And just at the point where the villain is shown leaning back to the farthest of his ability the film is cut and a dummy likeness of the villain is substituted for the fall, thereby saving the director's reputation and his standing with the real villain's family.
Then there is the close shot of the hero's fist landing with terrific impact on the villain's jaw and sending him sprawling. Naturally no villain really wants to feel the terrific impact of the hero's fist. The two boys may be good friends in real life. So the hero lets his fist fly gently and merely taps his opponent.
But, of course, this wouldn't look realistic on the screen so what does the director do or order the cutter to do? He cuts or orders to be cut every second or every third individual picture from the strip of film that shows the slowly moving fist. As a consequence of this cutting the movement of the fist is given actual speed and finally when the scene is shown on the screen it looks like the real thing!
Of course the old trick of the baby being rescued from the onrushing train in the nick of time or the scene of the automobile just cutting across in front of the thundering express are generally understood. The action is usually taken backwards as in the fight on the edge of the precipice with most satisfactory and thrilling results when shown on the screen frontwards.