Carl Theodor Dreyer's films were strange but important.

DANISH film director Carl Theodor Dreyer, who lived from 1889 to 1968, is unquestionably one of the most important figures in the history of cinema, and one of the strangest. The subject of a forthcoming retrospective at the Melbourne Cinematheque, his films are filled with mysteriously motivated cuts and slow, exquisitely calibrated camera movements. Whether the themes are Christian or secular, the atmosphere always suggests religious ritual: solemn, shadowy, hushed.

Few filmmakers make us more aware that the figures we are watching are phantoms, ghosts of human beings who once stood before the camera. The clocks that tick through Day of Wrath (1943), Ordet (1954) and Gertrud (1964) remind us that our own lives are disappearing, one second at a time.

Dreyer's horror film Vampyr (1931) ventures directly into a zone between life and death, with the hero, David Gray (Julian West), searching for the source of a contagion that enables corpses to prey on the living. Unforgettably, the happy ending is intercut with the death of a minor villain trapped in a mill, smothered in flour that pours forth like blood.

Much later Dreyer would deal with a different kind of resurrection in Ordet, a disconcerting Christian parable. In rural Denmark, a feud breaks out between two families who belong to different sects; death threatens the tolerant woman (Birgitte Federspiel) who has striven to bring them together. But a miracle occurs, as prophesied by Johannes (Preben Lerdorff Rye), a madman who identifies himself with Jesus.

Day of Wrath, a tale of witch-burning set in the 17th century, most clearly spells out the central conflict in Dreyer's work, between patriarchal law and a sensuality seen as life-giving yet potentially malign. This can be interpreted as an anti-religious film, but all its central narrative questions are left open: witchcraft is neither affirmed nor denied.

After a fairly prolific career during the silent period, Dreyer made only one feature film a decade: Vampyr in 1931, Day of Wrath in 1943 and Ordet in 1954. His swansong came in 1964 with Gertrud, a chamber piece based on a play by Hjalmar Soderberg, the story of an idealistic singer (Nina Pens Rode) whose principles lead her to reject one lover after another.

It's a great film in which one character, the poet Gabriel (Ebbe Rode), denies the existence of greatness: "The world is small, and people are small." Gertrud concludes that love is the only thing that matters but the full, reciprocal love of her dreams is nowhere to be found: not in this life.

Gertrud was attacked by some critics as theatrical, and so it is, in the sense that the limited space of a stage can suggest the limits of existence. So it is with the interior spaces of Gertrud with their sofas, paintings and desks, surfaces that refuse to yield a hidden meaning.

The shot of a closed door that ends the film arguably tells us no less or more than the famous close-ups in Passion of Joan of Arc (1929), which show Renee Falconetti straining towards a light invisible to the viewer. What these images mean is impossible to put into words: they say everything and nothing, inducing a sense of distraught fascination that is the keynote of Dreyer's work.

The Passion of Carl Dreyer, ACMI, until July 9.