Casablanca
Mise-en-scene
Much of the mise-en-scene is realist using period clothing and the setting and props being from that era, however there is a recurring theme of stripes. These are used to give a sense of imprisonment as they are all trapped in Casablanca.
Lighting
The lighting is quite formalist and though the film was made in a time when they could not film in colour they extend their use of black and white to using chiaroscuro lighting, which emphasizes the contrast between light and shadow. Ingmar Bergman's face is lit up to exaggerate her beauty. Sometimes it even seems like she's illuminated in the darkness, like an angel.
Camerawork
The camerawork clearly used a lot of cameras to get all the different angles shot in many of the scene. Instead of zooming in or panning it cuts to another camera, which gives you a more realistic view of the area because you cannot zoom into things in real life. For Ingmar Bergman much of the camerawork is shot from her left side as it was her preferred side. This makes the film seem more staged and gives it a slight formalist tinge. Another formalist aspect is the fact that they use a lot of close ups on facial expressions.
Editing
Actors
The leading male of the film is Humphrey Bogart who's career peak was in Casablanca. His rise to stardom began in 1941 when he starred in High Sierra and The Maltese Falcon and from these he became a cultural icon. Beforehand he was known for playing hard faced arrogant gangstars but his early 40's films completly changed that.
Based on a play.