Directed by Mike Leigh. Starring Timothy Spall. Rated PG

Mike Leigh was best known as a master of heightened (and inexpensive) working-class realism until 1999’s Topsy-Turvy—his colourful study of musical superstars Gilbert and Sullivan—got him high on period costumes and sets. Here, he’s again in biopic mode, if further back in the 19th century and in a more sombre, yet equally rewarding, visual realm.

Not long after 1800, John Mallord William Turner—embodied in a career-high performance by Timothy Spall—was acclaimed and sometimes controversial for his oil paintings and watercolours, which depicted vast and increasingly impressionistic seascapes, generations before French painters challenged the academy with their roughly dappled canvases.

None of the veteran writer-director’s previous efforts (such as Naked and Secrets & Lies) have been this painterly, although cinematographer Dick Pope worked on most of his kitchen-sink movies too. But their light-blasted visuals are less slavish re-creations of Turner’s images than faithful explorations of the places he wanted to capture. Still, the 150-minute tale, which concentrates on the final decades of Turner’s life and has some key musical moments, is more concerned with verbal expression.

The famously taciturn painter, whose father and closest friend (the Oscar-worthy Paul Jesson) was a humble barber, stayed enigmatic among his upper-class patrons, occasionally erupting in poetic epigrams such as “The sublime and the contradictory can be harmonious.” In a quote not used in the movie, Turner advised an art agent to explain, to one confused customer, “indistinctness is my forte.”

Elsewhere, he describes an ocean voyage as “execrable” and a local coach trip as “an English travail”. But Turner’s crucial form of communication, documented by contemporaries, was the porcine grunt, which becomes an oddly endearing expression, whether he’s seen touching up a painting before envious colleagues or shtupping his long-suffering, psoriasis-plagued housekeeper (Dorothy Atkinson), who was related to his first quasiwife (Ruth Sheen). All contradictions are present, if not always explained, in this unforgettable work of cinematic art, and the effect is never less than sublime.