Michael Apted is, by his own admission, a tough director to "nail."

Although he has an impressive résumé of dramatic films to his credit, including two multiple-Oscar nominees (1980's "Coal Miner's Daughter" and 1988's "Gorillas in the Mist"), the 66-year-old English filmmaker is arguably more highly regarded for his ongoing series of "Up" documentaries, a now-seven-film project that critic Roger Ebert has called, collectively, one of the top 10 works of cinema of all time. Beginning with "Seven Up!," a 1964 television show for which Apted served as a researcher, and continuing with last year's "49 Up," a theatrically released feature directed, like each of the previous five films, by Apted, the series chronicles the life changes undergone by a group of 7-year-old British schoolchildren at seven-year intervals, bringing to bear the storytelling power of narrative film.

In Washington recently to promote his newest film, "Amazing Grace" (see review on Page 31), a period drama based on the historic efforts of British politician William Wilberforce (1759-1833) to abolish the English slave trade, Apted acknowledges the slipperiness of what he calls the Apted brand. When pressed, he defines it as the overarching "documentarian spirit" infusing his work, even as he admits the absurdity of including some of his past films under that broad umbrella.

"But of course, that covers a multitude of things," he says. "How you could say James Bond presents a 'documentarian' brand is a bit. . . . " His voice trails off with a laugh at the incongruity of placing the 1999 film "The World Is Not Enough" (directed by -- guess who? -- Michael Apted) in the context of the rest of his oeuvre.

All of which makes him a bit of a conundrum for those who like to pigeonhole people. Still, Apted's proven ability to bring verisimilitude to fiction and drama to the documentary form has served him well in Hollywood, he says, ever since he made his American directorial debut with "Coal Miner's Daughter," based on the life of country singer Loretta Lynn. That he's now something of a go-to guy for "people who want stuff to look 'real,' whatever that means" may have as much to do with his track record as with the fact that he is one of very few people who can do what he does. "I really can't think of hardly anybody other than Jonathan Demme who does documentaries as well as feature films," Apted says. "I can't think of many other people that do that."

Not that the director is content to rest on his laurels. On the contrary, he describes, with some frustration, the incomplete level of reality he has managed to achieve in his feature films so far -- including "Grace" -- as merely a kind of "artificial" reality, one that still leaves him "hankering" for the kind of visceral, emotional truth found in such films as last year's "Half Nelson," a drama about a drug-addicted but inspiring junior high school teacher from director Ryan Fleck. Looking at that film, Apted says, one in which "you really can't believe that this isn't happening in front of you," made his "heart stop."

The director believes he has come closest to achieving that reaction with the "Up" series, but it's also where he'd love to get with a film like "Grace." "It's so difficult. I can't . . . I never really figured out how to pull that sort of thing off, to deal with the storytelling -- the structure of storytelling -- and the realities of Hollywood filmmaking, and my own education in films and stuff like this."

Telling Wilberforce's story was fraught with other difficulties, not the least of which was the fact that the project came to him as a conventional biopic, which Apted determinedly did not want to do. Rather, he says, what jumped out at him was the story's politics, especially since he had been casting about for material dealing with people's disengagement with public policy.

"I think politics is extremely important," Apted says. "And people disregard it and disrespect it. I think political action is extremely important, and political discussion is extremely important. It seems, over these last decades, that that's evaporated from the menu, in a sense. I think that's catastrophic, and I think people have become -- maybe this is horse [manure], but -- people have become alienated from politics and indifferent to politics, which is [first] not a good thing in itself, but secondly, allows for more political corruption, more political sleight of hand if people aren't paying attention to it. I think you have to pay attention to politics."

Once he had persuaded the film's producers to allow him to make a more talky film than they might have envisioned -- involving "a lot of people sitting down in rooms," as Apted puts it -- the filmmaker also had to deal with how to handle Wilberforce's evangelical Christianity, a delicate matter considering that the company behind the picture was Bristol Bay Productions, owned by politically and religiously conservative billionaire Philip Anschutz, who, among his many business interests, is publisher of the free Washington Examiner daily tabloid.

Were there concerns that the film might try to push a right-wing agenda? "Yes, of course, very much so," says Apted, who ultimately was able to convince the film's backers that the way to go was "not to disregard Wilberforce's Christianity but not to make it the center of the movie."

According to Apted, emphasizing Wilberforce's "principles" over his religious beliefs is not just smart business, but more true to life anyway.

As with the 2004 Ray Charles biography "Ray" -- another Bristol Bay film that Apted says was successful only because the film didn't "pussyfoot around" the singer's "women and his drugs and all that sort of stuff" -- "Amazing Grace" would have been a "train wreck" if it had made Wilberforce out to be some kind of saint.

"If you're going to go to a wider audience" than the evangelical community, says Apted, ever searching for the sweet spot between the bite of reality and the punch of drama, "you've got to deal with Wilberforce's humanity, and his strengths and weaknesses as a man."