Can you capture the moment? When first you hear rain on a roof? Some things are beyond the sum of their parts, expressing the poetry of life. The things that matter.

Poet Dylan Thomas captured the seemingly inexpressible "A good poem helps to . . . extend everyone's knowledge, of himself and the world around him." (Bob Dylan named himself after him). So why has it taken so long to make a film of the great Dylan Thomas? A simple biopic could have missed the point. Writer Sharman Macdonald has taken a different, better approach.

In The Edge of Love, she creates the world of passions and complexities that fill the poems so we can swim in them. The lives of four friends. Dylan, who lusts and loves to the full. Wife Caitlin (Sienna Miller), his feisty support. War-hero William (Cillian Murphy), who saves him from a street brawl. And then there's his childhood sweetheart. Vera. Dear Vera. Take your breath away Vera. She's Caitlin's closest friend. William's wife. And, like a muse, the 'star' in Dylan's dark sky.

It all kicks off in the 1940 London Blitz, with bomb shelters in the Underground. Enter Vera (an impressive Keira Knightley) under makeshift stage spotlights. She meets Dylan for the first time again in years, her heart is flushed. Their eyes shine through the smoke of the room. The purity of their former passion. Dylan (native Welsh-speaker, Matthew Rhys) is no sanctified, sanitised poet. Master of his vices he must experience them all fully. He introduces his beloved wife then continues to woo Vera.

The Edge of Love is a visual treat. The soundtrack leaves you wanting for more. Performances are possibly the best by these actors in their careers. As a lush love story it's pretty good. As an insight into Dylan Thomas and the reality of poetry in all our lives, not bad at all. And as a tribute to a great man, inspiring.

The production has been at pains to project the spirit of Dylan Thomas without compromising historical accuracy too much. Dramatic tension involves a pull between artistic freedom and conventional morality. Audiences looking for an experience based on the latter may be disappointed. And it will play less well to audiences whose boundaries are those of Albert Square.

Sharman Macdonald seemed aware of the headstrong nature of artistic freedom and its limits when she spoke to producer Rebekah Gilbertson (granddaughter of the real William and Vera). "Think of all the things that you don't want me to write about," she said," because I have to have carte blanche." For Macdonald, the limits were if she should cause offence to Dylan's memory. But for many artists, especially men, the limits are those which wife and family could set on them. A woman is not going to let lofty ideals interfere with practical common sense issues, and will even put her children's interests before her own (This occasionally happens the other way round, as when towering genius Virginia Woolf refused to let loving Leonard bring her down to earth - in The Hours).

In spite of the tension between Caitlin and Vera, these two women become closest buddies. It is one of the main (and very beautiful) themes of the film.

The film's colours tell a story in themselves. In a drab, wartime Britain, Caitlin and Vera are vivid highlights in an ocean of grey. Shortly after meeting Vera's lit-up-in-lights stage persona, we encounter Caitlin through her searing blue eyes, sparkling in a darkened railway carriage. Her dramatic red coat cuts a dash through streets of colourless homogeneity, triumphing on a beautiful staircase as she reunites with Dylan. But Vera's lipstick red brightness is less enduring. For her, marriage is second-best, even when she has become possessed with genuine love for her husband.

Outstanding cinematography extends to using montage to juxtapose images, in a manner similar to poetry's juxtaposition of unrelated words to create further meaning. Horrific war scenes in Thessaly are intercut with screams of Vera in pregnancy. Giving birth or is it abortion? We are not told immediately. Pain is universal and goes beyond time and place to our present day.

Constant echoes of Dylan's poetry throughout the film lead us beyond earthly opposites. It reminds me of Marlon Brando reading TS Eliot in Apocalypse Now. A light beyond the horrors of the world. A different way of seeing things. "I'll take you back to a time when no bombs fell from the sky and no-one died  ever," says Dylan to Vera as they walk along the beach. Elsewhere, Caitlin recalls childhood with Vera: "We're still innocent in Dylan," she says.

There's a time to leave your knickers at home or share a universal cigarette. (Not literally, perhaps.) A time to be inspired. Enjoy what is possibly the best British film of the year.

Sentiment: positive