The story about two total strangers meeting on a train and swapping a murder simply had not been in 1951 and Hitchcock's superb filmmaking earns high marks yet again. The amazing use of dutch camera angles, tilt shots, and shadows successfully pulls off the film noir feel of the film. There are many different scenes in the film where the lighting is particularly meaningful or effective to heighten the suspense, such as in the tunnel and the moving shadows, the bars of shadows on the faces of Bruno and Guy, and the surprise of Bruno emerging for the bed when he flips on the light. All of these examples as well as many others work quite well in the feeling and mood of the film.
The first example of the well thought out lighting is in the Tunnel of Love when Miriam, her two boyfriends and Bruno are shown inside the tunnel and we see their moving shadows. We see Bruno's shadows slowly getting closer and closer to Miriam and as the camera quickly cuts away just as his shadow overlaps hers, we hear a scream from inside, which turns out to be nothing more then Miriam yelling at one of her boyfriends with an "oh, stop that," meaning that it was unexpected and inappropriate. This sort of irony in the scene would not have worked if the audience was seeing the actors in natural light rather than their shadows on the tunnel.
Another example is the shadow of the bars on Bruno's face as he awaits Guy. The implied nature of the bars symbolize and foreshadow future complications with the law. It is clear that Hitchcock intended this scene to be lit this way. Along with the shadows of bars on the face of Bruno, the shadow on his face caused by his hat was also no accident. The darkness and evil side is to be revealed while he is in the shadows and by tilting his hat he is slowly developing into the crazed lunatic who wishes to frame Guy.
It is interesting to consider the contrast established by Guy's and Bruno's personalities, which we could define as totally complementary; the almost bright, trustful Guy and the cruel, dark and obsessive Bruno.
