Final answer:
Film noir was influenced by German expressionist films and the use of metaphoric images and unique camera angles in Russian cinema.
Step-by-step explanation:
Film noir was influenced by several factors. One of the major influences was the German expressionist movement in the early 1920s, which produced films like 'The Cabinet of Dr. Caligari' and explored challenging themes. These films used abstract sets and jarring compositions to create a sense of unease and critique society. Additionally, the Russian director Sergei Eisenstein used metaphoric images and unique camera angles in his films, which also influenced film noir.