Film can be a looking glass to see the world in a new light. Good Night and Good Luck, for instance, offered parallels to modern judgement-without-evidence and encroachments on freedom. It is easier to examine a moral problem when it is not too close to home: by putting it in a fictional or historic context removed from our immediate situation. With pornography, we consider ourselves 'enlightened' and our forefathers to be hidebound by quaint ideas - usually involving fire and brimstone, but the definition of what is obscene can easily fall prey to ignorance and unscientific interpretation instead of evidence. Bettie Page was a cult icon of an era which included not just McCarthyism but the banning of comics (such as Tales from the Crypt) on the basis that they would turn youths into half-mad juvenile delinquents. This film, developed from key questions raised in her life, poses dilemmas that are as relevant today as back in 1950.

Our film opens with two key scenes. In the first, we see well-dressed, respectable looking men in a seedy bookshop. One of them asks for pictures of women in kinky boots and being restrained - then turns out to be an undercover cop conducting a sting. The second scene shows Bettie Page, waiting to be called as a witness, looking quite demure, as if she had just come out of church.

The first 50mins are in black & white. Old fashioned film effects such as wipes and fades add to the sense that we are watching a film from bygone years, as do the mannerisms of the cast, skilfully recreated 1950s scenes, contemporaneous slang phrases and the terse dialogue associated with film-making of the period. Archive footage is frequently intercut - which will delight many and irritate others. In keeping with its theme, the movie is almost a collection of different types of photography-in-motion, and the older clips of fabulous beaches and landmarks juxtapose well against Bettie's classic poses hearken back to an age of 'health & nature' magazines . . . although I admit that if you are not captivated by the story you may find the effect a bit choppy.

Very soon, we go into flashback. Bettie escapes a Depression Years downtrodden life in Nashville, enlivened only with church singing and soul-saving, and goes alone to make her own way. After her initial success, her modelling work splits into two strands: the mainstream glamour work focussing on her over-the-rainbow smile, and the 'specialist interest' photos involving dressing up in high-heeled boots and light bondage gear. In an earlier audition (reminiscent of a scene with Naomi Watts' character in Mulholland Drive - who was also called Betty), she gives a performance that is full of emotion, contrasting with her normal animated, cheerful (but ultimately bland) day-to-day expression. Is part of her still unfulfilled? Bettie is frequently rejected in auditions once they realise she is the well-known pin-up girl. But we have never been asked to feel sorry for Bettie Page: her abusive childhood is quickly referenced and skipped over; when she is raped by four hometown lads, we see only the threat and then Bettie recovering and surviving, picking herself up in deserted woodland, and putting on the brave face of someone who refuses to lie down and die.

Although no nudity is involved, it's Bettie's special interest photos that eventually arouse trouble. When we go back to the court, the opinions of a clergyman on the corrupting influence of such photos are taken as evidence. A psychologist authoritatively says how the photos lead to 'suicide, murder and psychosis' in youngsters who are exposed to them (presumably not in that order). Eventually a star witness explains how his son's life came to an end as a result of such photos - 'being 'trussed up like that'. It is not made clear how being 'trussed up' causes death). The text accompanying a series of Bettie's photographs in a magazine tell how she was forced to endure 'terrible agonies' with the fetish restraints (the audience knows that she actually found them quite hilarious and that the wordings, like the photos themselves, were pure dramatisations). After a 12hr wait, Bettie is told her evidence - she is the one person who could state definitively that she was not photographed in agony - will 'not be required'. The 'horrors' of the photos have been proved.

If this all sounds like the dark ages which we have left, consider a recent (2003) incident in which an Ann Summers advert was banned. It said, "for fashion and passion whip along to your local store," with a photograph of a woman's back. She's wearing a bra and thong and her hands are handcuffed behind her back. The lingerie and sex toys company, that targets female consumers (and also supports charities fighting domestic violence) said its adverts aimed, "to give women sexual confidence and always showed women in control of their sexuality." One might conclude that the prejudice and ignorance of the Betty Page investigations still holds currency.

Bettie's religious views are integral to the story, just as the concept of sin is integral to Christianity and contributes to the 'forbidden' nature of sexual enjoyment frequently prevalent in the UK and US - as opposed to the more factual approach found in continental Europe. It could be argued the formulae of sin and redemption, and "being saved", are even reflected in mating patterns that perpetuate traditional male dominance. A policeman making a friendly (but sexually motivated) approach to Bettie outside the courtroom offers to 'save' her from loneliness. The knight-in-shining-armour might be chivalrous, but it also assumes a woman in need of rescue.

Love it or hate it, The Notorious Bettie Page is an unusual and extraordinary film, and a moral wake-up call for those that heed it. There is excellent ensemble acting, and Gretchen Mol, as Bettie, is remarkable as the whole film succeeds or falls on her powerful performance.