Directed by Lucy Walker, Karen Harley, João Jardim Club, IFi, Dublin, 99 min

THE LATEST documentary from Lucy Walker, the wunderkind behind such fine films as Devil's Playgroundand Blindsight, sounds suspiciously like a "good news story". There's a danger it might be inspiring, optimistic and so forth. Huh? This is not what you expect from a nominee for the best feature documentary Oscar. Those films are supposed to be about genocide, global warming and doomed penguins. Aren't they?

Walker's piece does, indeed, buzz with positivity. Waste Landconcerns itself with an epic project by Brazilian artist Vik Muniz. Over the space of three years, the amiable genius encouraged a group of so-called catadores– the people who scavenge on Rio de Janeiro's rubbish tips – to construct giant images from available trash.

Most are portraits of the workers. The spectacular one on the film's poster is a version of David's Death of Marat(as far as we can remember, no discarded baths were used in the reconstruction of that famous painting.) Later, after photographing the giant collages, Muniz made efforts to sell the pictures in a London auction house. Jokes about modern art being a pile of rubbish are foresworn.

Waste Landfeatures some stunning shots of the community in action. Vast heaps of steaming, stinking filth play host to the army of accidental environmentalists. The film is, however, most notable for a series of character studies that, though affectionate, never come across as being patronising. Tiaõ (ultimately portrayed as Marat) is the clear-headed president of the Association of Recycling Pickers of Jardim Gramacho. Zumbi, an autodidactic intellectual, is always on the look out for discarded paperbacks. Suelem supports her two kids by scavenging.

At times, the film does tend towards feel-good naivete. Life on the dump must, surely, be a little more, well, rubbish than it is represented here. The score by Moby surges at least once too often.

Howevever, such positivity is, in the end, preferable to presenting the poor as victims. Nobody likes to see documentarians turn into handwringing country schoolmarms.

All this noted, it will have to go some on Sunday night to beat that film about the thieving, lying, coke-snorting bankers. Now, that’s the weighty tone the Academy favours from its documentaries.