"What am I doing in this dump? I had it made!" So says Jerry Seinfeld as he tries out new material at a no-name comedy club in Comedian. The answer to his question - that the driven, semi-pathological nature of the successful stand-up comic compels him or her to perform in front of a live audience-fuels Christian Charles' fascinating and often very funny digital-video documentary.

Shot using available light in basement clubs, bars and after-hours gatherings, Comedian is a grungy look behind the comedy nightclub scene that uses a two-pronged approach to detail just what makes a comic tick. By far the most interesting tack is the in-depth chronicle of Seinfeld as he throws out all of his old material and starts from scratch to mount a new routine. Charles and crew follow him for eight months as he works one five-minute bit into a full hour of worthy material. Along the way, we are treated to the rare sight of Seinfeld bombing as he works out some new bits, accompanied by his self-lacerating comment, "You can't get any bigger than me and it's still shit."

Paralleling Seinfeld's return to form is the story of Orney Adams, a thoroughly obnoxious New York comic with "loser" written all over him. He combines a monumental ego with an equally large streak of insecurity, leaving him whining and miserable 24 hours per day. But he does have drive and a good work ethic, and is passably funny-which, contrary to first impressions, leads to a measure of success that culminates in a spot on Letterman.

Despite the frequently just-plain-ugly look of the DV transfer, Charles shows some wit and cinematic savvy via his use of great tunes on the soundtrack. The Band's version of Dylan's "When I Paint My Masterpiece" comes across as ironic counterpoint to Seinfeld's perfectionism-the point being that he'll never be satisfied enough to consider anything he does a masterpiece. At another point, as Seinfeld wends his way through a labyrinthine backstage area, Charles' camera follows him to the sounds of The Stones' "Can't You Hear Me Knocking," recalling Scorsese's similar Steadycam shot from Casino. A nice touch, that, as is Seinfeld's visit to the Museum of Radio and Television, where he looks at great old clips of a young Robert Klein and an even younger Richard Pryor.

What is revelatory here is just how much preparation the truly great comics do. They are ALWAYS working, whether it's in the car, sitting at home or hanging out in a banquette after hours at a club, swapping jokes and stories with their fellow comics. And by "fellow comics" I mean everyone you've ever heard of save Letterman: Robert Klein, Chris Rock, Jay Leno, Gary Shandling and dozens of other recognizable faces show up to contribute tidbits and anecdotes.

Which brings us to the man both Seinfeld and Chris Rock are completely in awe of-Bill Cosby. When Seinfeld learns that his hero has done a 2 1/2-hour show of new material that had them rolling in the aisles, the look of disbelief and admiration on his face is alone worth the price of admission. In Seinfeld's eyes, Cosby is the real Comedian.