Just because you collect hundreds of hours of moving images doesn’t mean you have a film. The fact is abundantly proven by “Convention,” a documentary that covers the 2008 Democratic National Convention without ever getting near a politician or even a political operative.

Instead, the filmmakers obsessively follow a clueless mayoral aide who is forever getting stuck on the wrong side of barricades, a pair of crusty but harmless hippies who have been protesting more or less everything since 1968, and a handful of reporters from the Denver Post, which was apparently under the impression that it was competing with the New York Times.

Everyone keeps turning to the camera and delivering their little talking points, but “Convention” bungles its only chance at a moment of unscripted drama — when a young reporter bursts into tears from stress and runs away from her desk — because the cameraman was evidently too reticent to follow and find out what was going through her head.

At the end, we catch a glimpse from the crowd as the anointed nominee waves to the crowd and confetti flies. Too bad we already saw that on TV, two years ago. Cinéma vérité? More like cinéma banalité.