Most of the time, "film" is treated as an uncountable. (stuff vs. things)
I'm out of film.
I don't have much film left.
I want to buy some 35mm film.
I'd like to buy three rolls of 35mm film. (not) I'd like to buy three 35mm films, although this is possible, and correct.
There was a lot of film on the cutting room floor.
Is there any film in your camera?
You have to think hard to come up with a common uncountable usage:
I need a film for my camera. I don't have a film in my camera.
Do you have an extra film for a Kodak Brownie?
Do you happen to have a Kodak Brownie film?
The uncountable is more likely: Do you happen to have any Kodak Brownie film?