In “Master of Light,” Rosa Ruth Boesten’s superbly intimate portrait of painter George Anthony Morton, shadows matter as much as light. The documentary, which won the grand jury prize at the SXSW Film Festival, deals with Black trauma, gently acknowledging change without over-trumpeting resilience.While serving time in federal prison for selling drugs, Morton studied the works of Rembrandt and other classical painters. Unlike too many formerly incarcerated people, he found work when he was released after a 10-year stint. He painted the portrait of the Black owner of a gym, which led to more painting.

“Master of Light” makes clear that just because Morton — who lives in Atlanta with his partner and young daughter — has found his calling doesn’t mean he’s at peace. And the film toggles between Atlanta and the Kansas City neighborhood of his ruptured youth, where he returns to paint portraits of some of his family members, using the style of the Dutch Masters he so admires.

When we meet Morton, he’s got a well-earned grasp of the outrages perpetrated by systemic racism, starting with mass incarceration. As a kid, he received encouragement in school to nourish his artistic talent, but the streets called. His critique of the “setup” that keeps people like him — and those who aren’t — perpetually hustling and failing is honed, even if it strikes familiar beats at times. In an energetic exchange with a sister who lives in Kansas City, the two talk about the schooling they received in the drug trade from their mother and grandmother. “She showed me how to cook that shit,” he says of his mother.

Boesten and cinematographer Jürgen Lisse make their own deft use of shadow and light. The documentary might have been called “The Chiaroscuro of George Anthony Morton.” There are moment when a shadow settles on Morton’s face like a cloud, like a thought darkening. Sometimes it is the latter; he has plenty of exchanges with his mother that put him in a grim mood. Other times, that shade is simply how the artist looks when sitting in front of a canvas amid painterly concentration.

In a contemplative moment, he recalls the effect of the Dutch Masters’ paintings on him. “Where’s that light coming from,” he wonders. “Why does it make me feel so alive and present?”

The light here emanates from Morton. His curiosity about art, about his place in the world after his incarceration, makes visible the darkness he’s experienced. There’s a reason we’re in the car with him as he drives to get his mother out of jail, or accompanying him around the Kansas City neighborhood of his youth or sitting in stillness as he talks with his therapist: He is our guide. The credits read “A film by Rosa Ruth Boesten & George Anthony Morton,” and “Master of Light” is a work of collaboration more than portraiture. (Also significant to the movie’s careful grace: producer and Oscar-winning documentarian Roger Ross Williams.)

The filmmaking is attentive and emotionally respectful. After a particularly volatile phone call between Morton and his mother, the camera quietly eyes Morton’s young daughter, who is standing at a remove in the hallway. There is a great deal of pain in the frame.

Conversations between Morton and his supportive partner, Ashley, occasionally grow prickly. When she says something critical about his mother’s selfishness, he shuts her down, saying she can’t know what his mother’s life has been like. Ashley did not grow up in the same devastating economic circumstances. In some sense their back-and-forth about his mother’s recurring troubles is a microcosm of the tensions around personal agency and the devastating effects of generational and communal trauma that are not carried by Black Americans equally.

Morton’s mother, who had him when she was 15, is a deeply complicated figure for him. Early in the film, he calls to ask if she saw him mentioned on a TV news program. Her disinterest is damning. Later, he learns that the story he went to prison believing about her role in his incarceration may not be the truth. That, too, is damning. They were arrested at the same time and did not see each other again for 13 years. That Morton wants to understand his mother, forgive his mother, makes for the film’s remarkably tender ache.

Many of the revealing moments in “Master of Light” aren’t about watching but about listening. Morton expresses doubt about visiting a therapist. But in their initial meeting, Morton shares that he likely has survivor’s guilt and that he’s experienced “a pretty unique form of trauma.” As their sessions deepen, Morton declares, “I want to be more light, less serious. I wonder if life has hardened me.”

A Black man with a vibe of equilibrium, the therapist gentles a young man who wasn’t brought up to seek — or trust — the profession. (Rap is our talking cure.) Therapy is “about transformation. Not about being fixed,” he tells Morton.

“Master of Light” is also about transformation. The exchanges that take place as Morton paints his mother, his romantic partner and 11-year-old nephew Treshon are their own form of working through. After Treshon recites a rap he’s written, Morton tells him, “I turn my pain into art too.”

The film concludes with Morton working on the portrait of his mother. There’s a hint of his face in hers in the not quite completed painting. The film ends with a subtle yet magnanimous gesture, making it clear Morton’s remarkable story is not yet finished — in the best possible sense.