Abbie Cornish as Fanny Brawne in Bright Star (dir Jane Campion, 2009) is chillingly mesmerising adorned in her widow's weeds - tho never married - at large in a snow-bound copse, her brother trailing dutifully after her having been sent on this important errand by his concerned mother (Kerry Fox). It is a formidable introduction for the youth to the power of love. And the subject of this film is love.

Yes, Keats died. Unloved by the public. Undiscovered by the critics. A bright star in the firmament of English poetry, Keats (Ben Whishaw) shone the beams of his intelligence into areas of the human soul that had long lay in darkness. But another achievement has been overlooked, for it is no mean thing to capture the heart of a girl.

The many colours of love, indeed. Keats' confidant, Mr Brown (Paul Schneider) rather eagerly and dishonourably exerted himself in embodying another form of love. The rather carefree Mr Brown in fact got the Brawne's maid Abigail (Antonia Campbell-Hughes) with child, married her under duress, and returned to survey the field after his friend died. Fanny is of course bereft.

Cornish is more than up to the task of playing the love-lorne Fanny. Collapsed at the foot of the stairs, Fanny gasps for breath. "Mama," she cries, "I can't breathe." "There is a holiness to the heart's affections," Keats had warned his friend Brown, on finding that he had sent Fanny a Valentine note. Knowing that Keats was fond of Fanny, Brown's paper dalliance was at least in poor taste. Fanny, luckily, is true to the end, and Campion keeps the camera focused firmly on the black-clad female who wanders in the chilly woods reciting her lover's wonderful verses.

It's not a complicated love story, although the costumes and the bare wooden floors try to transport us back in time to a simpler era. Those are excellent props, I found, and they are deployed meaningfully and without ostentation. The language, the domestic fittings, even the tiny wrapped letters - mark of a time when paper was an expensive luxury - generate the required quotient of authenticity. But we find that love was, then, just as it is now: a thing of wonder. Campion's restless camera lingers on a wide variety of 18th-century-looking scenes, but the real trick is that we never know what's going to happen next.

One key element is the friction that Fanny and Mr Brown generate when they appear together on camera. The slightly trumped-up Brown lacks Keats' genuine richness of vision and he compensates by indulging in cynical musings, finding Fanny lacks the qualities that should allow her to tie herself to the real poet. The friction generates rising heat, however, late in the film when Mr Brown returns to the Brawne's house with his new wife Abigail in tow. There is a menace within this menage that threatens the pure link between Keats and Fanny.

Campion's taste is excellent, too. She zooms in on delicate flowers, she lingers lovingly over a hand as it touches a wall, she relishes the original and lovely garments that talented Fanny creates with needle, scissors and thread. Campion's deep respect for Fanny's achievement is evident in the care she takes to render the romance in bright, fresh colours - the colours of butterfly wings and cherry blossoms and ripples on a cold, dark pond far out in the woods.

Highly recommended.