Who was it that said reading the entirety of Marcel Proust’s monumental novel can’t help but change one’s life — because one spends so much of life reading it? The statement came to mind while watching “Inside the Yellow Cocoon Shell,” the debut film from Vietnamese filmmaker Phạm Thiên Ân. A viewer won’t spend a lifetime watching it, but the minutes do rack up: It’s just shy of three hours.

That doesn’t, by definition, make it a long picture in terms of aesthetic experience. Movies can zip by quickly or move at a measured pace whatever their length. A good film creates and sustains its own logic, generating interest and tension through the employment of the medium’s internal dynamics. The quality of a given picture is, in significant part, dependent on how well it makes chronological time a moot point.

“Inside the Yellow Cocoon Shell” has been crafted with no little precision and an abundance of forethought. Mr. Ân’s knack for composition is second to none. The orchestration of the actors, both laterally across the screen and within the space of a given setting, is as calibrated as the movement of the camera — which, on the whole, moves gradually. Given that the majority of scenes are extended single takes, it makes sense that the director served as his own editor. Choreography, not montage, is the rule.

Mr. Ân leans heavily on his director of photography, Dinh Duy Hung, and sound editors, Vuong Gia Bao and Xander Toh, all of whom bring a jeweler’s attention to their jobs. Characters are obscured by screens or seen through windows in dark interiors. Their interactions are mediated by architecture when they aren’t engulfed within the verdant topography of the Vietnamese landscape. Voices and sounds, the latter more numerous than the former, achieve an almost preternatural import.

The film begins in Saigon with a trio of 20-something guys, one of whom is our protagonist Thien (Le Phong Vu). They’re sitting at an outdoor cafe, drinking, smoking, and discussing the nature and limitations of faith. A nearby motorcycle accident interrupts their digressions, but only briefly. Any thought extended toward those affected by the crash is waylaid by a trip to the sauna and a visit with a masseuse.

Thien has been doing his utmost to ignore the incessant buzzing of his cellphone. He ultimately picks up to learn that his 5-year-old nephew, Đạo (Nguyễn Thịnh), is in the emergency room. Đạo’s mother, Thien’s sister-in-law Teresa, has died in a motorcycle accident. Is this the same accident that happened earlier? Given the occluded nature of Mr. Ân’s screenplay, it’s best not to make ready assumptions.

Thien is tasked with the care of Đạo and brings him to the family’s hometown out in the sticks. As the funeral services take place, Thien is prompted to locate his older brother and Đạo’s father Tấm. Why Tấm abandoned his family and has long been incommunicado is a subject barely touched upon and never explicitly divulged. In the meantime, Thien reconnects with Thảo (Nguyễn Thị Trúc Quỳnh), a former paramour who has since become a nun.

It’s tempting to describe Thien and Thảo’s reunion as being dour in nature, but everyone in Mr. Mr. Ân’s picture is down at the mouth. A kind of existential lassitude blankets the movie and, with it, a begrudging way with dialogue. Only in a flashback to an earlier stage of Thien and Thảo’s relationship do we get any sense of engagement, vitality, or connectedness. 

Otherwise, a deadening uniformity of affect takes precedence, a kind of Bressonian tempering of emotions. Couple that with a tempo that doesn’t always differentiate between the fulsome and the indulgent, and you have a film of considerable merit that almost dares you to walk out on it. That one doesn’t is testament to Mr. Ân’s gifts. Still, a modicum of sweetening and shortening would make his humanism less chary and his art less daunting.