FILM / Woolf in chic clothing: Orlando (PG) Sally Potter (UK); Knife in the Water (PG) Roman Polanski (Pol); A Song for Beko Nizamettin Aric (Ger/Armenia)

Who's afraid of Virginia Woolf? Not Sally Potter, apparently. Three years ago, she was in Cannes with a glossy prospectus seeking top-up finance for her project to film Orlando. And finally it is here, achieved on a pounds 2m production budget that juggles Russian, French, Dutch, American, Italian and British money. On this miserly allowance, Potter creates, among other things: a lavish Elizabethan banquet; a Jacobean skating party on the frozen River Thames (this bit shot in Russia) during the great Frost of 1610; a Central Asian interlude; and a Georgian literary salon. Like (the otherwise very different) Leon the Pig Farmer, her film is a tacit reproach to the dim funding climate here, and a triumphant monument to determination.

You can see why moneymen were reluctant. Potter's previous credits - Thriller, a short essay on the female victim in opera, and The Gold Diggers, a meditation on women and money - were both more than a shade cerebral, like cleverly illustrated slide shows. But, with Orlando, she has taken the story of a young nobleman who lives for 400 years while barely ageing (although he does mysteriously become she half-way through), Potter has made very free with an odd, literary fantasy and refashioned it into an original, deeply enjoyable film.

It begins with Orlando (Tilda Swinton) at the court of the aged Queen Elizabeth I, who makes him her favourite and confers upon him the boon of immortality. Quentin Crisp as the queen is inspired casting, and not just for his gentle, dignified presence. He, and the male falsetto who serenades the Royal Barge idling languidly down the river, create an instant mood of fluid, epicene sexuality and heft the film over its biggest credibility gap - encouraging the audience to accept, right from the start, its trickiest conceit, Swinton as an impulsive, beardless youth. And, as an 'alternative' institution - a self-styled 'stately homo of England' - Crisp signals one of Orlando's other keynote themes, national pride and self-delusion.

By an odd paradox, Orlando risks attacks from two implacably opposed camps: on the one flank from critics of the safe-but-dull period drama, on the other from enemies of the pretentiously obscure art movie. But Orlando blends and modifies both these traditions, as elegantly and as wittily as, 10 years ago, an eccentric avant-gardist called Peter Greenaway transmogrified the hoary old country house murder mystery in The Draughtsman's Contract.

It's true that the costumes are sumptuous, the sets opulent, the stream of meals, feasts, soirees and receptions conucopian, the source eminently literary, and the struggle over wealth and property (Orlando's stately family seat, quickly wrested from him when he goes female), one of the main themes, as seen in Brideshead Revisited, Howards End - as a matter of fact in Britpix passim.

But Potter distances herself from many of these films' usual assumptions - she sees Orlando's loss of all she owns as a matchless personal liberation, for instance, rather than a tragedy. The story has a promiscuous internationalism, with its cast of Russian, American and Asian exotics; it views the 'privilege' of being English with a sceptical eye, seeking out images like the Ice Ball, which sets a mincing minuet against cossacks skating round in soaring free-form patterns. Most strikingly, there is Swinton's constant ironic address to camera - wry comments or just a flickering, raised-eyebrow glance that offer flashes of a mocking and distinctly modern viewpoint.

Potter's avant-garde background is worn; in fact some elements of Woolf's story have, if anything, become more conventional. There, Orlando was quite a lusty young blood, but as the film's rather traditional poster (an embrace between Swinton and Billy Zane) suggests, it takes Zane's romantic adventurer, thundering out of the mists in high Victorian-Gothic style, to bring some belated sex into the proceedings.

Compared to the weighty didacticism of Potter's earlier work, Orlando skims lightly over its ideas, not pressing points too eagerly. Indeed you'd be forgiven for not buying into some of the story's core premisses - that People are People, regardless of their gender; or that Orlando has been miraculously transformed from hack poetaster to gifted novelist.

But there is much else to relish: the film displays the visual gorgeousness of Jarman and Greenaway (no accident, this, since Potter uses those directors' brilliant costume and production designers), without sinking into their pessimism; it has a light, playful touch and ends on a note of curious, irresistible exhiliration.

Further proof that less is often more comes from Knife in the Water, Roman Polanski's first (and only Polish) feature, which everyone favourably compared to his expensive turkey Bitter Moon when the latter was released last year. The two films are both set on boats, both detonate charged erotic confrontations. But the difference is not just a question of budget. Knife has just three actors and, mostly, a single location - a small yacht. Polanski makes virtuoso use of his tiny location, taking the camera in the cabin, up the mast, into the sea, ringing the changes in his characters' power-plays with strange, dynamic over-the-shoulder angles and skewed compositions.

In it, a middle-class couple invite a young hitchhiker along for a sailing weekend to relieve their mutual boredom. The husband sees an opportunity to show off and pull rank: he soon has his cabin boy swabbing the deck. The wife, enigmatic behind vintage Sixties batwing specs, looks on bored as the men lock horns, while also noting the pecs on the bronzed newcomer. Everything is oblique, allegorical (guess what the knife signifies); where Bitter Moon casts a glaring light into every dark corner of its characters' obsessions, here the louring sex and violence don't break until the very end.

A Song for Beko, which plays in the ICA's Kurdish Festival, is the story of a refugee who flees from Turkey to Iraq to, after witnessing all kinds of horrors, Germany. It claims to be the first film in the Kurdish language and is certainly worthy but a tad dull: hard to recommend when some outstanding films by the late Yilmaz Guney (including his masterpiece Yol, which touches on the Kurdish question) are screening next door, in the ICA Cinematheque.