I have on previous occasions said, that I prefer Film Noir as a period, even more as a narrative field, than a subgenre. And zedz post made me want to elaborate on this.
It doesn't matter who identifies a "genre", what matters is that it is identified and is functional within its narrative limits.
Any genre is a collection of narrative elements and conventions by which a group of films can be identified, classified and recognized. They work, not because those who use them use them, but because the audience respond to them. It always has been the audience and always will be the audience who by their response approve of a technique or genre.
A genre is a living organisme, partly because the audience change, partly because society changes, but mainly because narrative elements aren't absolutes. And here is where the director is important, as a simple repetition of genre conventions rather fast will turn into cliche, and only the director who understands the rules of the genre, will be able to bend them, expand them and thereby participate in the development of the genre.
It is very true that the filmmakers who made "Film Noir" before it was identified as such, wasn't aware of they made it. I believe it was Robert Mitchum who said, "Hell, we just called them B-pictures".
They were making detective stories, gangster films, crime dramas. It was an attitude towards the world, a cynicism, it was a tone in the dialogue, a mood. It was an attack on male masculinity (which even during the post-war Film Noir period was present i films not associated with noir, like "Rebel without a cause"). It was a whole bunch of things put together, things which after noir was identified as "Film Noir" didn't change, but continued to develop and eventually died out.
From that perspective, it makes no sense to approach Film Noir as a subgenre, but it makes sense to approch it as a period within the bounderies of a group of subgenres (detective, gangster and so on).
Within genre, periods are very important. For instance musicals. There are the early sound period, the classic period, the modern period and the contemporary period. What limits each period is limited by its own rules, narrative fields and so on. One narrative element which seperates the classic from the modern is the use of "singing". In the classic, the story would come to a halt when a song appeared, while the modern musical would incorperate the song in the narrative and use it to elaborate on situation or character. Now take a film like "The Mask" and the Cuban Pete sequence. The song does not elaborate on anything, it brings the narrative to a halt, so it must be a neo-classic musical element. No one would say this. One would say, that the film incorperated a so and so musical number in a so and so way, perhaps noting on homage and allusion.
So why is it, that the mere presence of a single element from Film Noir suddenly overrules everything and makes it a neo-noir?
When a filmmaker is paying homage in this way I think it's fair enough to define their work as neo-noir
No its not. I strongly disagree. Homage is to pay respect, its about showing where one is coming from and what brought one here. Its acknowledgement. Its transtextual, as it puts one text in relation to another.
For instance, Jim McBride paid homage to the Nouvelle Vague with "Breathless", but would you ever think of calling it neo-nouvelle vague? But many are calling "Klute" a neo-noir simply because of Fonda's femme-fatale like character. As far I am concerned, the only true homage to film noir is "Body Heat".