The last years in the life of John Keats, one of the greatest of English Romantic poets, and in particular his difficult love affair with Fanny Brawne, are the subject of Jane Campion’s first film in six years. The hiatus seems to have been worth it. After disasters like “Holy Smoke” and “In the Cut,” “Bright Star” represents something of a return to form. It may not reach the heights of “An Angel at My Table” or “The Piano,” but it’s a mellow, pictorially engaging period piece in which the characters seem actually to breathe rather than merely pose, as so often happens in such films.

Ben Whishaw plays the poet, twenty-five and the author of “Endymion” when he first appears in 1821 as the houseguest of the brusque, sometimes brutally protective Mr. Brown (Paul Schneider). Nearby, Fanny Brawne (Abbie Cornish) has taken up residence with her mother (Kerry Fox) and younger brother Samuel (Thomas Brodie-Sangster) and sister Toots (Edie Martin). She finds poetry beyond her, preferring to design and sew her own dresses. But if his writing doesn’t immediately attract her, Keats himself certainly does. And the poet, despite her mother’s insistence that so impecunious a young man would be an impossible match and the jealous Brown’s determination to keep them apart, becomes entranced with her without quite comprehending why.

As Campion tells it, this is a story of young love that neither party can resist. And as such it’s reasonably effective: both Whishaw and Cornish are attractive and winning, and make the suffering involved in the thwarting of their relationship affecting, and the film’s depictions of them enjoying the natural beauty of their surroundings adds a truly romantic aura to it (the cinematography by Greg Fraser brings a delicacy and color to their scenes together that enhance the mood). Paul Schneider’s high-octane turn as the volatile Brown is also a plus, as are the supporting cast, including Fox as the sympathetic but practical mother, winsome little Martin as the precocious child Toots and Brodie-Sangster as the long-suffering younger brother who must serve as a virtual chaperone for his unwed sister for propriety’s sake.

That detail points to one of the picture’s chief strengths: it gets the social structures governing nineteenth-century romance among a certain class of society right, as Jane Austen did in her books. And it portrays the relationship in the chaste, rigidly controlled form it would have had. There’s a sense of decorum and discretion that simply feels authentic.

And unlike so many period pictures, Campion’s doesn’t overly prettify the past, despite the atmosphere of fragile beauty it aims to create. The rooms appear genuinely lived in, and the clothes actually worn. The costumes by Janet Patterson are especially worthy of note. They look as though they were hand-made without the mechanistic precision of modern products; they often don’t seem to hang quite right on people, and in the case of Fanny’s designs, they’re often quite peculiar. And Brown’s unbecoming plaid trousers go along perfectly with his thick Scottish accent.

Other details add to the ambiance, often in throwaway fashion. A party scene in which a male chorus offers an a capella version of a movement from a Mozart serenade captures the kind of entertainment that would have prevailed in private home before phonographs were invented. And a moment in which Toots and Samuel are shown, offhandedly, doing ballet exercises under the tutelage of a dance master suggests, without emphasizing it, the breadth that an education required in the upper-middle-class England of the early nineteenth century.

Of course, none of this detail can obscure the fact that we know where this story is headed; we’re not dealing with “Inglourious Basterds,” and history is not going to be rewritten here. Nor can Campion overcome a common problem in films about writers and painters: it’s practically impossible to depict the creative process convincingly, or in this case to capture the essence of Keats’s art; occasional recitations of passages from his poems really aren’t enough, and academic-sounding descriptions of his posthumous influence aren’t capable of fully expressing how important his compositions were to later British culture.

But that’s a difficulty that filmmakers, even those of great ability, have always had in trying to fashion portraits of artists as young men or old ones, and one can’t really blame Campion for failing to crack what may well be an insuperable problem of the genre. Compared to other biographical films about poets, “Bright Star” ranks high, and simply on its own terms it’s an attractive, affecting depiction of doomed young love that wears its period trappings lightly.