While Rick's face has indeed become more brightly lit, this can especially be seen in the lighting used for Ilsa. Ilsa's face is illuminated by bright white light, giving her an almost angelic look. This use of light gives a sense of romance between the two characters that otherwise might be lost if the scene was shot in darker lighting. It is as if the presence of Ilsa in the bar has not only lit up the room, but has changed something in Rick himself, which is expressed by the change in his lighting. This technique helps to show the various emotions in the characters, as well as add depth to Rick's character who before seemed very stern and unemotional. The way Ilsa's face is lit up during a long close up shot while Sam is playing the piano also provides insight into this character's emotions. During this close up shot it is clear that Ilsa is in deep thought, reflecting on her past with Rick. The intense lighting used on her helps to convey the similarly intense emotions she is feeling. .
Another scene in which lighting is used to convey the emotions of the characters is when Rick is drinking in his bar after Ilsa has gone. This is the first time in the film where Rick's weakness has become apparent. The lighting has once again switched to very harsh and dark, but even more so than before. One side of Rick's face is almost completely lost in shadows, while the other half is still illuminated. This choice of lighting shows the two sides of his personality; while he seems rough on the exterior, his more emotional and soft side is now shown. This dark lighting in this scene also helps to show how broken up Rick feels after seeing Ilsa, and the sadness and despair he feels from losing her. Upon reflecting on his relationship with Ilsa, a flash back sequence begins. During this flashback the lighting immediately changes to a much brighter light giving the sense of daytime, where most of Casablanca takes place during night.
