I Am Heath Ledger, Grade: B

Available on digital and DVD on Tuesday.

It seemed the world was just getting to know Heath Ledger, an Australian actor with rock-star charisma, when he died in January 2008. He was only 28 years old, but already he had rocketed through several stages of his career: The dreamy leading man in 10 Things I Hate About You, the straight star who played gay in Brokeback Mountain and, most famously, the psychotic Joker in Christopher Nolan’s The Dark Knight. That breathtaking performance seemed to announce the arrival of a new Brando, Pacino or Daniel Day-Lewis.

Instead, Ledger became the new James Dean. While filming Terry Gilliam’s The Imaginarium of Doctor Parnassus, Ledger died of an accidental overdose of prescription medications. I Am Heath Ledger, which premiered at last month’s Tribeca Film Festival, makes the case that the young actor was only beginning to tap into his full potential.

Any time a fast-rising talent dies young, his story can become romanticized and mythologized. I Am Heath Ledger falls into that trap at times, painting its subject as a larger-than-life figure who burned too bright for our world. Nevertheless, I Am Heath Ledger, directed by Derik Murray (whose I Am series includes Chris Farley and Evel Knievel), offers several interesting angles on Ledger as an artist and as a person.

The first surprise is that Ledger carried a camera — either still or video — at nearly all times, and much of his personal footage provides the basis for this film. Some of the segments are fascinating. We see a snippet of Ledger practicing the twitch that would become the Joker’s smile, along with an extended sequence of the actor racing through a hotel on a secret “mission.”

(He never breaks character, even around baffled bellhops.) The first is an example of craft, the second an exercise in commitment — two hallmarks of Ledger’s finest performances.

We also get a sense of life within Ledger’s orbit, and it looks like fun. Naomi Watts and Ben Mendelsohn (Rogue One) describe Ledger’s Los Angeles home as a crash-pad for Aussie actors of all stripes, be they successful or struggling. “I had nothing going on, work-wise,” says Mendelsohn. “And it sort of didn’t matter.”

For the musician Ben Harper, a close friend, Ledger’s generosity came in the form of a grand piano delivered to his home.

There are two notable absences here. One is Ledger’s former partner and mother to his child, Michelle Williams (though she has given this film her blessing). The other is Nolan, who directed Ledger in a performance that earned a rare posthumous Oscar.

Still, family members and friends provide a vivid picture of Ledger as a creative whirlwind whose next career move was to direct. (Ledger planned to adapt Walter Tevis’ cult novel The Queen’s Gambit into a film.)

“The truth is, he was happy and living life,” said Ledger’s agent, Steve Alexander, of the actor’s final months.

“He wasn’t wanting to go anywhere but forward.”