Fifty Shades Of Grey (18)

Before seeing this adaptation of the first of EL James's bewilderingly successful erotic romances, I had less curiosity about how director Sam Taylor-Johnson would bring its S&M sex scenes to the screen, than what she would do with the rest of the book's monumental hogwash.

On the page, James's heroine Anastasia Steele is a blithering idiot, who belies her college education by surviving on half a dozen expressions - "holy cow" being the most common - while endlessly biting her lip and conducting a dialogue between her "inner goddess" and her subconscious that deserves far more than a spank.

Compared to James, Dan Brown seems like a poet laureate. So the film really couldn't be worse than the book. Might it be better?

The answer is a heavily conditional 'yes'. The good news is that screenwriter Kelly Marcel has avoided the temptation of a voiceover, ditching Ana's inner voice and therefore sparing us James's moronic prose; this, allied to a feisty and funny performance by Dakota Johnson, presents a romantic heroine actually worth our time.

But the bad - and surprising - news is that Taylor-Johnson (Nowhere Boy) offers almost nothing as a director, in particular delivering sex scenes that are needlessly tasteful and tame. The result is less risible than it might have been, but just as bland, the "mommy porn" of the book now playing as Mills & Boon with the softest of soft-core kinks.

No time is wasted in introducing the English Literature student to billionaire bachelor Grey (Jamie Dornan), she being sent to interview him for the college newspaper. And it's good fun. Johnson has the demure and clumsy Ana in place, but allows something behind the eyes, an ironic awareness of all that is silly about the encounter, accompanied by believable, barely contained lust.

Johnson also has the voice of her actress mother, Melanie Griffith, with its breathy, little-girl vulnerability that suggests something held in reserve; and this is what we see in the film's other stand-out scenes - the comic negotiation over Grey's S&M contract (with all the things that Ana crosses off probably unprintable here) and the "climax", in which it's clear that the parties will have to return to the negotiating table.

In between, we follow Grey's unusual courtship, urging the virginal and besotted Ana into a relationship in which he won't do love, only sex of a "singular" nature. While Ana contemplates playing submissive to his dominant, he introduces her to "vanilla" sex, while plying her with first editions, a new car and a ride in his helicopter; there is chivalry when she is drunk, but also a stalker's tendency to turn up when she least expects it.

There was always the potential in James's material for something darker and psychologically interesting, residing in Grey's motivations, not least the question as to why he switched from being a submissive, himself, to a dominant. Dutiful to their source, Marcel and Taylor-Johnson leave the stone unturned, restricting poor Jamie Dornan to the limited explanation that "it's the way I am."

The Belfast actor, who was so chilling as a serial killer in TV's The Fall, is slightly at sea here. He's got a body that sent the several hundred women at the film's London premiere into hysterical yelps, dispenses his character's innuendo with aplomb and tries hard for intensity; yet the film's overall, cheesy tone steers clear of what he has to offer.

And with the sexual explicitness of the book greatly watered down, Fifty Shades quickly loses steam once Ana enters the "red room of pain" - and we realise that what we're about to see inside isn't going to be half as painful as reading the book.