For more than half a century, documentary films existed only at the margins of cinema, embraced by a small filmmaking community and remaining relatively unnoticed in the mainstream. That’s why many moviegoers are unaware of the genre’s long and storied history, assuming, as they do, that most docs look and sound like “March of the Penguins.” It’s probably a surprise, then, that the first breakthrough documentary was filmed in 1922 by Robert Flaherty, the director generally considered the father of the form.

With “Nanook of the North,” Flaherty (1884-1951) had set out to capture a year in the life of an Inuit family near the Arctic Circle — a first for filmmaking. But since its debut, scholars have questioned the veracity of Flaherty’s footage, debating which elements of the film were staged and which were real. Flaherty made no secret about the fact that he had recruited the cast for his nonfiction film, and that some of the scenes were contrived so that the filmmaker could obtain the images. Thus, from its very origin, the documentary form has provoked discussions of the way the elements of fiction and nonfiction can influence each other, as well as the way filmmakers can influence their subject matters.

When Flaherty died in 1951, he left a legacy of astonishing work, from the 1931 collaboration with F.W. Murnau, “Tabu,” to the 1934 Aran Island documentary “Man of Aran” and the 1937 fictional film “Elephant Boy.” Constantly challenging himself to cross thresholds and test the boundaries of the documentary form, Flaherty never stopped breaking new ground. After his death, his widow, Frances, launched the Flaherty Seminar on the family’s farm in Vermont, an event at which filmmakers and scholars could gather to watch and discuss her late husband’s work.

The inaugural seminar was held in 1955, before the dawn of the film-school era, and its collaborative focus was a novel idea. Frances Flaherty invited people not just to view films and measure their success, but to examine the artist’s evolving techniques and influences.

Eventually, the annual Flaherty Seminar expanded beyond its namesake’s work — not to mention Frances Flaherty’s farm — and moved to nearby venues in upstate New York, where it focused on an expanding catalog of films. It continues that focus even today. In recent years, curators at the Museum of Modern Art have organized annual screenings by pulling from films that were chosen from the seminar. On Friday, the annual Flaherty Seminar will arrive for the first time at the Brooklyn Academy of Music for a special three-day presentation of works.

“At the seminar, so many of the New York filmmakers we screen and those who attend, they all live in Brooklyn, so it’s about time that we bring this to Brooklyn audiences,” the seminar’s executive director, Mary Kerr, said. “One of our newer initiatives has been to make the seminar more accessible to more people — to make it easier for audiences to see the films we work all year to program.”

The series, titled “The Age of Migration,” promises to explore “how hybrid documentaries, video Web logs, and personal narratives have become vehicles which collapse physical distances and connect people to their homelands and their histories.” Friday’s headlining film, “Calavera Highway,” is a personal documentary by Renee Tajima-Peña that uses a road trip as a way of resurrecting family memories. Saturday’s spotlighted film, Kent MacKenzie’s renowned “The Exiles” (1961), follows a day in the life of a group of American Indian friends in Los Angeles’s Bunker Hill neighborhood in the pre-civil rights 1950s.

But Ms. Kerr points to Sunday’s roster as “the best single program to learn about the migration issues that we explored at the seminar this year.” The evening is made up of three short films: the 58-minute “God Is My Safest Bunker,” the 29-minute “Cargo,” and the 5-minute “The Form of the Good.”

“These are films that really capture the themes,” Ms. Kerr said. “James Hong, who directed ‘Form of the Good,’ makes films that are more political experiments and somewhat controversial. Laura Waddington directed ‘Cargo,’ in which she traveled on these cargo ships and recorded the lives of these people who live onboard, always living between borders without a home country.”

Various speakers are scheduled to present films between Friday and Sunday. Lee Wang, director of “God Is My Safest Bunker,” will speak Sunday evening and the Tribeca Film Institute’s Lucila Moctezuma will introduce “Calavera Highway” on Friday.

Ms. Kerr was careful to point out, though, that one needn’t attend BAM’s Flaherty series to get a sense of the experimentation that now pervades the documentary field. The lasting impact and spirit of Flaherty’s work can be experienced regularly on New York’s art-house screens. The forthcoming New York Film Festival, for example, will include such films as the historical memoir “Waltz with Bashir” and the biography-autobiography hybrid “The Windmill Movie,” two titles that toy with standard nonfiction storytelling techniques.

Even “Man on Wire,” one of this year’s most successful nonfiction films, makes liberal use of re-enactments and narrative techniques. “It’s a beautiful film, and whether they realize it or not, they are continuing the Robert Flaherty tradition,” Ms. Kerr said. “Documentaries are becoming a little bit more accessible in the movie theater, but you still have to constantly be doing something different to appeal to the masses. You have to get your film to stand above the standard, informative work. Some people think of Flaherty as the father of the documentary film, but back in the day he was more of an experimental filmmaker than anything else.”

ssnyder@nysun.com