The legendary actress Faye Dunaway is just as mercurial as ever in “Faye,” a new HBO documentary about her life and work that will have its premiere this Saturday. Before we even see her, with elegant shots of New York appearing on screen, we hear Ms. Dunaway impatiently instructing the doc’s filmmakers to begin shooting. 

Then, when we do see her, seated on a couch, and director Laurent Bouzereau reminds her that it’s the anniversary of her winning an Oscar for “Network” and the famous poolside photograph taken to commemorate the moment, her demeanor changes. Her eyes light up and her jaw relaxes into a smile as she recounts a high point in her career. 

A few minutes later in the film, after we’ve watched several commentators describe their admiration of her and her work, we get another testy moment. As she repositions herself for more questions, she admonishes an off-camera assistant: “I need a glass of water, not a bottle.” 

As iconic Dunaway lines go, it may not be up there with her “No wire hangers ever” roar from “Mommie Dearest,” or even, “Could you leave please? You’re right in my eyeline,” the clip of which made the rounds on social media a couple months ago. Yet the water demand sizzles with the same mixture of severity and fastidiousness that has come to define Ms. Dunaway’s persona, both on-screen and off.

Besides the behind-the-scenes glimpses, Monsieur Bouzereau employs a standard mix of documentary tools to tell the performer’s story: movie clips, photographs, stock footage, talking-head observations, and both contemporary and dated interviews. While this format goes through each stage of her life dutifully, the narrative nonetheless proves riveting due to brisk editing and the eloquence Ms. Dunaway brings to its telling. It also helps that many of the movies she starred in merit multiple viewings. 

Born in Florida in 1941, the actress discusses her upbringing as the daughter of a non-commissioned Army officer and an ambitious mother. As is customary with a parent in the military, the family moved around a lot, with her parents eventually divorcing. The young Faye would playact as a way of escaping the despondent aspects of home life, such as her father’s alcoholism, though she clarifies that her childhood was not only a miserable one. Later on, she also asserts that “success is freedom,” and it’s refreshing to see a celebrity speak so intelligently and challenge dominant narratives about unhappy upbringings and fame. 

Ms. Dunaway headed to New York to study with Elia Kazan after graduating from Boston University with a degree in theater. From there, only a short time passed before Hollywood came knocking. Once the account arrives at “Bonnie and Clyde,” the classic 1967 film about the infamous pair of Depression-era bank robbers, the documentary makes the case that several movies in which Ms. Dunwaway appeared were reflective of the tumultuous times of the late 1960s and ’70s.

Ms. Dunaway not only reflected the new, independent woman of the era in “Bonnie and Clyde,” “Oklahoma Crude,” “Chinatown,” and “Network,” but the pictures themselves mirrored the nation’s rising violence, corporatization, and corruption. Yet entertainments like “The Thomas Crown Affair” displayed her flair for modern and sexy capers as well, with journalist Robin Morgan calling that picture’s wordless chess game scene “the most erotic piece of filmmaking ever made.” 

While her love life is brought up now and then, such as her affair with Italian actor Marcello Mastroianni, and Ms. Dunway’s status as a fashion icon gets a cursory mention, the subject that receives the most attention — apart from her indelible acting, of course — is her reputation for being difficult. 

After discussing the little-known film “Puzzle of a Downfall Child,” which tells the story of a dissolute, unstable model, the actress admits in a candid moment to being bipolar. She goes on to mention a “biological imbalance” and helpful medications, while simultaneously taking responsibility for her past actions. Still, the film implies that without her sometimes lacerating, exacting intensity, her performances would not have been as affecting. And she doesn’t exactly regret her behavior either, primarily saving her remorse for starring in “Mommie Dearest.”

The film’s analysis of the Joan Crawford biopic turns out to be quite incisive and unexpectedly poignant, involving as it does a couple of her co-stars. Indeed, when the filmmakers move on, one concludes that the 1981 movie deserves a dedicated documentary exploring its production and cultural impact. As the film winds down, one also wishes for a looser, alternative doc that makes time for observations of Faye’s quirkier career choices, such as her egg-eating commercial for a Japanese luxury retailer and her foray into reality television with “The Starlet.” 

Scenes of Ms. Dunaway’s adopted son Liam, now an adult, give viewers a sense of their relationship, and the documentary leaves us touched by their devotion to each other. Ultimately, though, the renowned actress’s dedication to her craft is the film’s biggest takeaway, with its spot-on selection of movie clips reflecting how Faye Dunaway in her heyday was both a movie star and a character actress, a force of nature and a sensitive soul.