The two children in the movie are the real-life children of director Carlos Reygadas. The family scenes were shot at his own house.
The film was made in the 4:3 (1.37:1) aspect ratio because of the landscape with steep mountains, and to achieve compositions with a clearly framed centre. 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.
The title is Latin for "Light after darkness".
Contemporary reviews for Post Tenebras Lux were far more divided than those for Reygadas' previous works. Some considered the film to be incoherent or frustrating in structure, while others have declared it a masterpiece.