Delia (Kyra Sedgwick) crosses the street, her blue-jeaned hips swinging. The camera follows her, close on what the narrator (John Ventimiglia) calls her “strong, heavy ass.” So far, so much standard objectification of a female backside. But it’s soon clear that Rebecca Miller’s Personal Velocity has more on its mind, and this jaunty image becomes oddly subjective. Delia understands how you might see her (what that standard backside shot means), and while she’s proud of her ass, aware of its power, more than anything, she knows its -- and her -- limits.

Delia's is the first of "Three Portraits" in Miller's film, adapted from her collection of seven short stories, and winner of the Grand Jury Prize at Sundance last year. Much like that first glance at Delia, the film gives good surface, courtesy of Miller's spare, observational prose and Ellen Kuras' incisively agile digital video work. At the same time, it raises good questions about that surface, about what you're looking at, and, more importantly, how you're looking.

Delia's tale quickly descends from that moment of self-confidence to a dreadful scene at dinner. As her three kids look on, her husband, Kurt (David Warshovsky), launches into a horrific, unprovoked and apparently routine rage, slamming her head into the table. Hiding in the closet, her kids screaming and Kurt mumbling his sincere and self-surprised apology, Delia comes to a realization: It's time to leave. She sneaks out while Kurt's asleep, first to a shelter ("Delia didn't talk about her problems. She intimidated the other women with her silence") and then to an old classmate's garage.

As she begins to see herself again, reflected in eyes that are not Kurt's, Delia also sees the distinction and connections between her self-image and her responsibilities to her kids. The film helpfully flashes back to her childhood, when she learned how to use sex to her advantage, despite and because of her own sense of distance: "Delia felt separate from her breasts and kind of awed by them." She appears jerking off a series of equally awed boys: "They were powerless, rapt. She did it for free; it was her vocation." That Delia, now waitressing at a stereotypically dingy diner, reclaims herself through just such activity, is unsurprising, sad and moving: Following an encounter with a local kid (Leo Fitzpatrick) who recalls her high school conquests, she sits in her car, framed by her windshield, caught and resilient.

Where Delia's self-awareness feels intuitive (she doesn't talk much), the second section, "Greta," features a painfully articulate Manhattan cookbook editor (Parker Posey). She long ago gave up law school to resist her big-deal attorney father (Ron Leibman) and now she's feeling increasingly frustrated with her alternative career and worse, with terminally sweet grad-student husband, Lee (Tim Guinee). Though Greta has access to more resources than Delia, she's facing similar limits of expectations and desires: hers and everyone else's.

Greta suddenly lands a choice job editing a young superstar's second novel (because he's heard of her ruthless cutting). She begins to test herself, cheating on Lee with the charismatic, self-absorbed writer (though, as a flashback reveals, such behavior isn't new for her), celebrating her promotion at a party thrown by her father, to whom she hasn't spoken in years. She's changed, Greta tells herself, she has ambition. And now, she's "going to dump her beautiful husband like a redundant paragraph."

Greta's self-awareness and selfishness are less admirable than awful, but the film makes it easy to follow her thinking. Paula (Fairuza Balk) is slightly less transparent, a kohl-eyed punk also desperate for change, following a freak car accident that kills her companion, whom she's only just met at a bar. (The film's "gimmick" comes in here -- all the stories touch on the story of this accident, underlining that they all take place at the same time.) When Paula picks up a young hitchhiker whose extensively bruised body reveals a history of abuse, she's moved to rethink her own priorities.

Balk has always been a physical performer, her limbs weirdly expressive; here, she's subtler and looser, perhaps inspired by the liveliness of that little digital camera. Paula's story, like the others in Personal Velocity, allows sympathy without resorting to heavy-handed redemption, insight without instruction. Imperfect and shifty, the film never stops moving.