AS PRACTICAL PRODUCTION THEORY a steal-o-matic that attempts to define Film Noir
"Strange as it may seem, I don't consider "Sin City" to be true noir for two reasons:
One: The primary thrill in noir shouldn't be violence, but instead psychological tension.
Two: Moral ambiguity. The film forces a "good/bad guy" thing on the audience; even though all the heroes are anti-heroes by most standards, by the film's standards they are infallibly in the right. A proper noir should be somewhat apathetic in it's dealing with ethics."
Film Noir is also about intense emotions and psychological complexity. People struggling to make the right choice or somesone who has a dirty past and has been running from it and he decide that it is enough and is about time he should comfort his past. See It all falls down.
One: The primary thrill in noir shouldn't be violence, but instead psychological tension.
Two: Moral ambiguity. The film forces a "good/bad guy" thing on the audience; even though all the heroes are anti-heroes by most standards, by the film's standards they are infallibly in the right. A proper noir should be somewhat apathetic in it's dealing with ethics."