The Maysles brothers film the uncelebrated

``We delight in making films of people who would otherwise be totally unknown,'' says Albert Maysles, who -- with his brother David -- has become well known doing just that. True, the Maysles have been known to deal with famous folks. Documentaries on Marlon Brando, the Beatles, and author Truman Capote are among their early credits.

But their most celebrated films focus on uncelebrated people, whose lives take on new resonance under the steadfast gaze of the Maysles camera. ``Salesman'' was a portrait of door-to-door Bible peddlers, and ``Grey Gardens'' visited a pair of charmingly offbeat women in a dilapidated Long Island mansion.

Although some Maysles movies have played the theatrical circuit -- and their Rolling Stones picture, ``Gimme Shelter,'' was something of a hit -- there's no big money to be made from documentaries. So the brothers finance their work by making sponsored films and commercials. If you've missed their major features, you may have caught one of their ads on TV or one of their ``industrial'' pictures at a company meeting.

Talking about their work in their large Manhattan studio, which seems close to bursting with busy workers and high-tech equipment, the brothers speak casually of their knack for juggling such different kinds of filmmaking. While made-for-hire movies pay the bills, personal projects monopolize their interest -- and they take pride in the spontaneous, ready-for-anything attitude that sets them apart from many documentarists.

``It's quite a thing to pull off a whole movie with four Bible salesmen,'' says Albert, the soft-spoken one, who's the cameraman of the team. ``They themselves didn't think there was a movie in it, and they couldn't understand why we were spending all this time and money. But when you take care of details and avoid cosmetics -- that's when you're making a real movie!''

At the heart of the brothers' work is ``a basic belief in photography,'' as Albert puts it. ``We don't think of Hollywood films as photography,'' he says. ``To us, photography is a direct process where camerawork and events take place at exactly the same time.''

For the Maysles brothers, this isn't just a definition but a professional credo. ``Photography gives knowledge of the real world,'' Albert explains. ``And philosophically, we believe this is exactly what the world needs.

``There's so much going on that separates us from the real world,'' he continues. ``Even movies! When you come out of a Hollywood picture, you know it's only a movie and there's nothing to be concerned about. When you come out of `Grey Gardens' there's a shock, because the life you just saw is real. I don't want to go overboard in my enthusiasm, but in a sense, it's the only moral kind of film.''

The idea of morality runs throughout Maysles filmmaking. ``We're even moralistic about who we take money from,'' Albert says with a smile. ``We don't want to owe people or have to please them. We want to please our sense of responsibility and setting the record straight.''

In creating their serious works, the only obligation that Albert or David will accept is toward their subject -- which makes their movies more responsible than ordinary pictures, in their view. ``When we depict the `Grey Gardens' women,'' says Albert, ``we have an obligation to them that we wouldn't have to a fictional character. The film is taking an active part in the real world as well as being a reflection of it.''

``What we do is like anthropology,'' says Albert. ``We're not getting anyone to do something for the camera. We're not controlling things and ending up with something artificial.''

To be truly scientific, one must not impose an outside perspective on people or events, and this also suits the brothers. ``We aren't message filmmakers,'' Albert explains. ``If you start with a point of view, then setting the record straight takes second place to another purpose: using the film to support your own beliefs or ideology.''

In this area, most documentaries don't meet the high Maysles standard. ``You'd think a documentary would be primarily factual,'' says Albert, ``but many are just the opposite. They represent an attempt to move someone politically. Or they've been funded by somebody, and they have to achieve some purpose or effect that's stated at the beginning.''

The brothers also have ideas about their effect on audiences. ``We want to make truly adult films,'' says Albert, ``that will move people to exercise their own maturity. We accept the audience as able to make up its own mind. You know a film has worked if it arouses as much controversy as the people would in living their own lives. . . .''

Recent films have put the brothers back in contact with the famous, through commissioned portraits of musicians Seiji Ozawa and Vladimir Horowitz. But upcoming works return to the ordinary folks who are their favorite subjects. In a new twist, the brothers plan to make their next films individually -- working separately for the first time.

Albert's project is called ``Fellow Passengers'' and will be shot entirely on trains during several two-week trips. ``It will be the ultimate test of our method,'' says the filmmaker. ``I'll have to get people's trust immediately, even though we're literally strangers on a train.'' Despite the limitations of time and territory, he's convinced that fascinating human material awaits him on the rails. ``The most personal stories and the fastest relationships can spring up on trains between people who have never met,'' he says.

David's new project is tentatively called ``Blue Yonder'' and will explore the lives of ``our two heroes: our father, who died in 1945, and a cousin who died in 1948.'' David sees these men as fascinating figures -- the former a postal clerk in a dead-letter office, the latter an adventurous fighter pilot. ``They were opposites,'' says David, ``and I never know which one I want to be. Those two characters are in all our films.''

Is it contradictory for David to see these family heroes -- or other personal concerns -- in documentaries he has made about outside people, and events?

He doesn't think so. ``All our films are autobiographical. Most people make documentaries from allegiance to some sociological interest. Our impulses come more out of our families and lives.''

Does this mean documentary-making can be a form of intimate self-expression? ``Yes,'' says David, ``in the same way that Eugene O'Neill and Tennessee Williams wrote out of their own lives.''

Albert agrees. ``It's not the same as an artist who takes a clear canvas and creates something where nothing existed before,'' he grants. ``But if you take several filmmakers and give them the same subject -- an event, an election, the bringing up of a child -- each will come up with something different. That difference is self-expression. . . .''