Chiaroscuro

Chiaroscuro found its origins in the Renaissance period and used strong contrasts between dark and light in its compositions. The use of light can draw attention to certain details or its lack thereof can conceal them entirely, requiring a closer examination of what is being represented. The connotations between light and life, and death, darkness and the unknown have long been associated with one another, and this presence has been explored and enhanced through the use of chiaroscuro by many artists,  notably Caravaggio.

St. Jerome

Renowned for his unorthodox realism and exaggerated chiaroscuro (which became known as Tenebrism),  Caravaggio lived a volatile life and was often arrested for brawling. After one of these brawls resulted in him killing someone, a death warrant was placed on his head and he fled Rome.

His later works exhibit his anxieties surrounding the possibility of his impending death, incorporating  self-portraits into biblical tableus that feature depictions of decapitation shrouded in shadow.

Judith Beheading Holofernes

Salome with the Head of John the Baptist

David with the Head of Goliath

Chiaroscuro found continued use with the advent of photography and later cinema. Many have observed the inextricable relationship between photography and death. Both being representative of an eternal stasis, photography captures an image of a frozen moment in time, gone forever, just as in death the subjects time is now past and they are forever condemned to stillness.

In classic cinema the use of shadow would accentuate all of the qualities inherent in noir storytelling; the deception and danger that is concealed from the vulnerable protagonist through a web of seduction and lies that threatens to consume him is perfectly represented by the connotations between shadows and that which is unknown.

Cinematographers such as Robert Krasker and John Alton capitalised on the use of Chiaroscuro to enhance the mystery surrounding characters and create a brooding atmosphere typical of post-war era films that borrows heavily from German Expressionism.

The most prominent film of this movement is The Cabinet of Dr. Caligari (1920) which succeeds in projecting the subjective interior of a character into the exterior. The characters are surrounded by jagged shadows throughout which later come to greater prominence with their knife-like resemblance which reflects Cesare's intentions of killing.

Robert Krasker's cinematography in Carol Reeds noir thriller The Third Man (1949) casts heavy shadows from buildings to counter the dramatic lighting and envelope the characters into the unknown, favouring low angles to aid concealment. 

 The atmosphere created by the combination of harsh lighting and distorted camera angles can perhaps be best evidenced in the climatic chase through the sewers of Vienna as Orson Welles' character Harry Lime is pursued by the police. This youtube clip has inexplicably replaced the iconic score with 'Ich Will' by German industrial-metal band Rammstein, which though perplexing and perhaps even seen as defilement for some, the inclusion of Rammstein can only ever improve something in my opinion. (Perhaps the user was making a tenuous connection between Austrian sewers and German Metallers? I'm at a bit of a loss...) 

Ridley Scott's Neo-noir masterpiece Bladerunner (1982) casts its characters in shadow from artificial lights usually positioned behind them to reflect their doubts over the nature of their reality, and whether or not they are artificial 'replicants'. 

(I didn't mean to bombard this many images but there is just to much awesomeness concerning this film and omission proved too difficult)

When Rachel is introduced she is illuminated by the sun, however her face becomes cloaked in shadow when she is being tested as she begins to doubt whether or not she is really alive. Deckard is often cast in a similar light (or lack of) as his status as a possible replicant remains ambiguous throughout the film and is subject to interpretation. (There are several different cuts of the film, some which confirm his being a replicant and others which affirm his humanity)