German Expressionism

Preluded Film Noir during WWII in Germany. The demand for films skyrocketed as foreign imports were suspended.
Expressionism takes stylisation to the extreme using canted angles and optical illusions to excite the spectator. Its roots come from the very core of film with George Melies, who was the first person to use the camera to trick an audience, who created the fictional genre of film with thinks like 'A Trip to the Moon'. Melies took expressionism to the point of hand-painting the individual frames of his film to give the audience more enjoyment. From the very start of cinema there was conflict between the expressionistic and the realistic with the Lumiere Brothers sticking firmly to realism.

Many of the films made during the German Expressionist Era were used to work out the emotions of the German public in the wake of the rise of Hitler. While it was never made an official film movement it inspired the Noir Movement of later years and the genre that continued on from it.
The exaggerated visual and generally macabre tone inspired the tragic hero of the Noir. The classical, heavily lined eyes and gaunt looking actors associated with the period also came about as part of the movement. It was during this movement that the montage was first invented after Melies invented the first jump-cut and editing to film. Soon after, camera tracking became more popular and films began to look less and less like stage performances. One such famous film was Eisenstein's 'Battleship Potemkin' where the sequence knows as Odessa's Steps introduced the concept of montage.

This also demonstrates the Kuleshov effect which was another cinematic technique that came about with the German Expressionist movement. The idea being that by cutting from a person to different images the mood of the entire piece changes. Hitchcock himself explained this effect.

All of this is explained in this film essay with reference to some of the most famous German Expressionist films such as 'The Cabinet of Dr Calagari' - Weine 1920 and 'Nosferatu' - Marnau 1922. Made by the same director (Marnau) as 'Sunrise'. 'Nosferatu' containing the same play on shadows and movement as 'Sunrise' - 1927. Another good example is 'Metropolis' - Lang 1927.

Characteristics:

Any work of art in which the representation of reality is distorted in order to convey and inner vision

Avant-Garde strain of modernism

Expressionism opposed impressionism or naturalism

Seeks the essence of things, rather than the way things appear

Undertone of dark seduction

Seeks an objects most expressive aspect (overlays, shadow and enlarging aspects)

Reality is entirely the creation of minds and wills

Characters are bearers of ideas

Messianic call for a new man

Chiaroscuro - dark/light

Predilection for the studio (sets)

Emphasis on shapes, forms and patterns

Tendency towards abstraction

Distortion, angularity and extreme verticals

Hypnotic and nightmarish worlds

Obsession with doubles (harmless semblance and more sinister counterpart)

Constant play with artifice and illusion

World of fakes, frauds, simulation and shape-shifters

Stylistic action (highly gesticulatory and fervent)
Characters sometimes become functions of set design and architecture
Can be about films and filmmaking
Narratives involving framing devices (painted backgrounds)
Themes of seeing and creation
Characters who arrange scenes (appearing in front of shop windows)
Cities and Constant Motion
Obvious Symbolism

Dehumanisation

Biomechanical Acting

Expression of Inner Thought and Emotion

Put the viewer in the mind of the main character through visual aesthetics (hence abstract design)

Key Themes of Expressionism:

Madness/Insanity

Betrayal

Horror

Death/Fatality 

Often uses these in reference to the emotions surrounding WW1 with elements such as mind-control, resurrection/the undead and an overwhelming sense of darkness/doom/mortality.