The film is semiautobiographical, and the narrative follows a rural couple in Mexico, with additional scenes from England, Spain and Belgium; all places where Reygadas has lived.

Seven (Willebaldo Torres), a man who usually does everything in his power to survive, leads him to Alcoholics Anonymous meetings in a ramshackle cabin in the woods.

[6] Many story elements are directly autobiographical, although the director has stressed that the film is partially about desire and fantasies, so everything has not taken place in reality.

Exterior scenes were shot with a distortion effect around the edges; this was inspired by the impressionists and their fascination with outdoors motifs, as well as by the view from an old, not entirely smooth glass window.

Robert Abele of the Los Angeles Times described it as "real rarity in cinema, a visually striking archaeology of the psyche that benefits both the moviegoer primed to engage Reygadas' ideas, and the ones open to being swallowed in an art film wave".

[11] In a largely positive review, Manohla Dargis of The New York Times wrote, "Everything in the film may be in the past or may just be in the eternal, magnificent, maddening present that is Mr. Reygadas’s consciousness.

Young expressed admiration for Reygadas' previous film Silent Light, but wrote: "Suspicions that the critically-lauded, award-laden Mexican is, in artistic terms, an emperor clad in exquisitely invisible garments will only crystallize further thanks to Post Tenebras Lux—which at its worst exudes the sort of smug pretentiousness that gives art-cinema a bad name in many quarters.

"[13] In Screen International, Jonathan Romney wrote: "Alexis Zabé's vividly beautiful photography variously makes the images seem spontaneously caught, or deliberately framed and fixed in a video art manner—and it could be argued that this film has much more in common with gallery video than with most contemporary theatrical art cinema...