When I watched the film "The cabinet of Dr Caligari" I felt in love with the Expressionism. I think, more than the paintings, the films was the most accurated piece of art in the expressionism movement. Beautiful and terrible.
From Germany, in the begins of XX century, the picture expressionism was carry out by to groups: Blaue Reiter (Blue rider/horseman) and Die Brücke (The bridge). Artists like Franz Marc or Edvard Munch worked with strong and impulsive colors, exaggerated and broken lines, trying to express, very literal, the anguish and desperation, against the french Impressionism, that only shows the appearence of the things.
The films presents that visual ideas, without color, but with movement and sound (piano music, of course, because was muted films). The most important film directors was Robert Weine and F. W Murnau. Weine directed "The cabinet of Dr Caligari", a strange and beautiful film about a sonambulist and muderer man. Filmed only in studios, was the oportunity to show all the visual aesthetics of expressionism in the sets.
One of the other famous expressionism films is Murnau's "Nosferatu". Boarding the vampire's myth, the film is a big piece of expressionism art. The dark and depressed feeling is reflected in the sets, in the make up, in the clothing, like a long scream of anguish and blood.
I can see hundred of times that films and every time I can feel it power again.