Noah Baumbach and Jake Paltrow's documentary is a vital portrait, regardless of what you think of its subject.

More rewarding for neophytes and casual fans than it is for the titular director’s hardcore devotees, Noah Baumbach and Jake Paltrow’s “De Palma” is nevertheless essential viewing for everyone. Part autobiography and part filmmaking master class, this chronological documentary tour through the life and work of Brian De Palma (“Carrie,” “Blow Out,” “Body Double,” etc.) might initially appear to be nothing more than a glorified DVD bonus feature — it basically consists of a comprehensive interview that’s interspersed with a clips from his movies and a smattering of choice archival footage — but it isn’t long before it begins to pick up speed and snowball into something special.

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Which isn’t to say that Baumbach and Paltrow don’t come out swinging, as “De Palma” kicks off with the opening scene of “Vertigo” and immediately confronts its subject’s notorious (and singular) obsession with all things Alfred Hitchcock. Serving as the doc’s hyper-loquacious narrator, De Palma offers himself up as the one true apprentice of suspense without hesitation, as candid about his relationship with Hitchcock as he is about the one he failed to develop with his estranged father. As you watch the 75-year-old New Jersey native lean back on his haunches and orate about his life with the comfort of someone who’s already left his will on film, it soon becomes clear that a documentary about Brian De Palma can’t succeed without answering one fundamental question: What is there to learn about him that his endlessly self-reflexive movies haven’t taught us already?

Plenty, it turns out. A large part of what makes “De Palma” great is that the film’s most resonant takeaways aren’t limited to its namesake, but the biographical stuff is still a joy to hear firsthand. De Palma is a born storyteller, and you don’t have to be one of those “Mission to Mars” defenders (you know who you are) to find yourself hanging on his every word.

He talks about seeing “Vertigo” with his family at Radio City Music Hall, he talks about being asked to tape the all-girls sex-ed class during high school, and he talks about the chance meeting with a young Robert De Niro that led to the actor’s very first role (in De Palma’s 1969 “The Wedding Party”). Baumbach and Paltrow edit out the space between their subject’s thoughts, and so it often feels as though De Palma is talking about all of these things in the span of a single breath.

READ MORE: Brian De Palma on Why He’ll Never Work for Hollywood or Television Again

Unsurprisingly, considering when De Palma rose to prominence, this doc is also an oral history of Hollywood’s greatest generation of brat geniuses. De Palma constantly invokes his pals like “Marty” and “Steven” and “Pauline,” packing multitudes of personal backstory within every throwaway line (“Steven and I were so close back then…” Back then! What happened??). For added flavor, Baumbach and Paltrow also throw in home video footage of Spielberg using a car phone as he drives around Los Angeles with some girls in the back seat and rings up De Palma over Thanksgiving — these 20 seconds alone are worth the price of admission.

But the film, while never dull, doesn’t achieve liftoff until De Palma starts talking about how “Dressed to Kill” was inspired by his childhood memories of following his father around as he cheated on his mother. Suddenly, after 43 minutes of listening to the auteur discuss his life and his work with unwavering gusto, it crystallizes that they’re one and the same thing.

That may seem to be self-evident, but hearing De Palma quote the budgets and box office stats of his movies like he’s telling you his blood type — or watching the utter lack of change in his face as he mentions his divorce as the true coda of “Bonfire of the Vanities” — you can feel the Hollywood machine breaking down into its individual parts (“The Hollywood system does nothing but destroy you,” De Palma sighs).

To some extent, the film is a feature-length argument for the auteur theory, albeit it one more intent on proving the concept’s validity than its merits. “De Palma” doesn’t argue that each of the director’s elaborate camera moves can be traced back to a traumatic episode from his youth, but it vividly illustrates why watching “Sisters” (or even “Snake Eyes”) might tell you more about the man through images than he ever could with words.

Fortunately, this movie isn’t about him. While “De Palma” is as wild, hypnotic, egocentric, and stubborn as any of the director’s films, it gathers them together and extrapolates some unrelated truths from the wide shot. “Let’s get one thing clear about directors’ careers,” De Palma declares, “We don’t plan them out.”

Baumbach and Paltrow’s rigidly organized documentary makes that quite obvious. But by sprinting through 50 years of features so fast that each of them ultimately feels like a single frame rattling through a projector, they blur De Palma’s body of work into a moving truth that none of his individual films has ever crystallized with such clarity: The movies are real-life; the great filmmakers are the ones who never let you forget that.

Grade: B+

“De Palma” opens in theaters on Friday.

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