At Cannes, Stanley Kubrick's mysterious right-hand man steps out of the shadows

CANNES, France - When Leon Vitali was working on Stanley Kubrick's

Full Metal Jacket

, he became involved in a disagreement with the director over the size of cabins in the shoot.

"I got a phone call at 8 o'clock. 'Your measurements are off by miles,' " Vitali, Kubrick's longtime aide-de-camp and subject of the new documentary Filmworker, recalled the director telling him.

"It was 'Leon . . . Leon . . . Leon, you are off,' " Vitali said, repeating Kubrick's choice of obscenity. "I said, 'Stanley . . . Stanley . . . Stanley, I am not.' Ten minutes later, Stanley called back and said, 'I'm sorry. I was given wrong information.' "

Vitali drew a breath. "That was one of the times I got an apology from him."

Fans of Kubrick know well how exacting the director could be. Far less recognized is the person who helped him carry out that exactitude, and who endured some of its harshest consequences.

For nearly a quarter-century after Barry Lyndon, Vitali - a successful British TV actor earlier in his career - served as Kubrick's right-hand man. After starring as Lord Bullingdon in that 1975 period piece, Vitali shifted roles to work behind the scenes on signature Kubrick movies such as The Shining, Full Metal Jacket, and Eyes Wide Shut.

Filmworker is, in part, a profile in absentia of Kubrick, one of moviedom's most studied and at times misunderstood masters. But by spotlighting Vitali, an insanely devoted man who lived in that master's shadow, Tony Zierra's documentary also illuminates a unique picture of creativity and its costs.

To explain Vitali's job is to try to trace the path of a worker ant. The best description might be the Kubrick Whisperer. At various points, the diminutive Brit was - unofficially and often unexpectedly - a casting agent, an editor, a title translator, an on-set manual laborer, a foreign-license negotiator, a color-corrector, an actor workshopper, and a marketing adviser. And a dozen other jobs that came up as needed, all because Kubrick trusted only him to handle them.

"I'd work 14-, 16-hour shifts, seven days a week," Vitali said of his time on sets or at Kubrick's British compound. "It wasn't like that some of the time," he clarified. "It was just normal."

Zierra, an indie filmmaker from Boston, started out making a very different movie - a film about Eyes Wide Shut that was to serve as a corrective of sorts to what he sees as the misunderstood legacy of Kubrick's final complete work. He spent more than five years on that project. But it all changed when Zierra met Vitali, who now lives in Southern California, and encountered the stacks of boxes filled with Kubrick notebooks, props, photos, and other artifacts he has in his house.

"It was amazing to discover that this guy who lives off Venice Boulevard by himself is the key to one of the greatest filmmakers of our time," Zierra said. "I thought, 'This should be the person people are hearing about.' "

Vitali was so close to Kubrick - and so present on the set - that actor Matthew Modine says in the film other actors thought he was a spy for the director, dispatched to report on their misdemeanors. He wasn't. He did get sent to fire actors, though.

The day before Filmworker premiered - the title comes from how Vitali describes his job on immigration forms, "assistant" being too narrow a label - Vitali was drinking a soda in the lobby bar of a hotel, having arrived in Cannes for the first time ever 24 hours before. Super-svelte at 68, with long hair hanging below a bandana, he combines the renegade spirit of a classic rocker with the solicitousness of a mail room assistant.

Such fierce loyalty to a high-powered director, of course, meant a less fulfilling, more fraught relationship with his three children, now grown. "Some would say it was selfish. But I don't think so. The only self-interest I had was working with Stanley because he was my absolute hero," Vitali said. He also gave up a promising acting career to do so.

Vitali doesn't view any of Kubrick's films as reflective of his own legacy. "To me, it was just about solving the problem. If things worked out and Stanley liked the actor or the layout or something else, that was great, for a moment," he said. "But there was always a new challenge" - such as enduring 50 takes of a scene in Eyes Wide Shut to perfectly sync a street-stop of Tom Cruise's walking character with the halting of a camera on a dolly.

Does Vitali think that Kubrick, if he were alive, would break a longstanding no-festival policy and go to Cannes to see the celebration of his longtime aide?

"I'd like to think he's up there somewhere watching this movie," Vitali said. "And editing it."