Check out this article on documentary filmmaking, by acclaimed director Michael Moore. I'm certain that all of the world's sound recordists rejoiced upon reading point #13,
Sound is more important than picture.
...You've been in a movie theater where it's been out of focus just a little bit or maybe the frame is spilling over onto the curtain. Nobody gets up, nobody says anything, nobody goes and tells the projectionist. But if the sound goes out, there is a riot in the theater, right?
That is to say, budget accordingly for your production. Don't count on your camera operator to collect clean audio. He or she has other things to worry about. The sound is critical to your story, and without it, your final product will suffer.