While Casablanca (1942; Michael Curtiz\Arthur Edeson, ASC) is widely acknowledged as one of the greatest movies ever made, it’s also one of the best-photographed. In addition to its brilliant images, it contains some amazing bits of technique that are noticeable to only the sharpest-eyed viewer.
At about the nineteen-minute mark, Bogart leads Claude Raines into a room where he continues off-camera into a nook, screen right. As Bogie then opens a safe to retrieve some money, his actions cast a shadow on the wall between himself and Raines, who waits on the left. We can clearly tell what he’s doing, though the message is that he’s being somewhat secretive.
The effect is clever and works beautifully; it no doubt enhances an otherwise dull moment for its audience. But its mechanics don’t hold up to close inspection. From the angle at which he’s standing, it is impossible for Bogart to create the type of shadow that appears on the wall. It’s too perfect, with none of the lengthening or distortion that would result from the light source on the far right of the screen. Instead, the shadow is almost squarely perpendicular to the lens.
The explanation for this is simple. The “wall” upon which Bogart’s shadow resides is actually made of semi-opaque fabric. While a stand-in mimicked his actions on the far side, a light from behind gave birth to a perfectly-matched silhouette. The stand-in’s timing is perfect and the trick is worth watching over and over just to appreciate its ingenuity.
Though we perform our magic digitally now, visual sleight of hand is nothing new. There’s an even more interesting shot of this kind in 1939’s Gone With the Wind, but I’ll save that one for another post.
Meanwhile, have a look at the clip and let me know what you think!