Cherchez the photographer, I always say

David Bailey's "The Birth of the Cool" retrospective opened at the Barbican on Thursday. Three hundred photographs, mostly black and white, of people mostly famous, are on display. Jean Shrimpton, the model with whom Bailey is most associated, is shown then, in the 1960s, and now, in a picture Bailey says he "gently had to twist her arm" to get - Shrimpton is now quite photo-shy. John Lennon is draped like a shawl (a favourite Bailey pose for coupled portraits) around Paul McCartney's head and shoulders. No such intimacy for the Krays: the brothers look like cardboard cut-outs. "I was always nervous around Ron in case he took a fancy to me," Bailey has said.

This exhibition has its faults, but it is because of them that I left smiling and thanking God for photographs. If I'd had a three-hour dinner with Bailey involving 20 beers - unlikely, as I hear he no longer drinks - I don't think I would have had greater insight into him. It is true that the camera never lies: but not about its subject-matter. If you want to know about someone, don't look at a picture of them, but at the pictures they take.

Bailey likes to set himself up as a sexist, arrogant "fat boy" (and he could certainly play a good Santa now; those pretty looks that might have tempted Ron have long since melted). Yet the photos in this exhibition (which ostensibly cover the years from 1957 to 1969, with some unnecessary intrusion from the 1990s) suggest a different man. For one, in these early pictures, all his women are treated with a reverence that betray him. Back then, he was still under the benevolent influence of the matriarchs in his family, his beloved mother and the oft-referred-to "Aunt Dolly".

Later on, however, his laddish tendency to "show off the wife" would mutate into something less respectful. In 1980, Bailey published Trouble and Strife, in which his then-wife, Marie Helvin, is shown in naked, often subservient, poses. In one photograph, she is depicted wrapped in newspaper and "discarded" in the attic with nothing but her cha cha showing. That was followed in 1995 by The Lady is a Tramp, this time showing his current wife, Catherine Dyer, in poses on the toilet and making love to other women.

I think Bailey got it wrong with these projects, not for reasons of misogyny (and it would be insulting to Helvin and Dyer to suggest they could be forced to do something they didn't want to do, although Helvin is said to have regretted it later), but rather, because Bailey didn't need to do something so unoriginal and so unsexy. His best pictures have an eroticism that comes from behind the lens, not in front of it.

Photography really works best when it's subtle, when not everything is presented to us on a plate. In 1930 Lee Miller (Man Ray's girlfriend) took one of my favourite photos, favourite because it's so evocative, it works your mind. Called The Exploding Hand, it shows a lady's hand reaching for the handle on a glass door. That's all you can see. You can tell she is inside a shop (a jeweller's shop, as it turns out) because the reflection of the outside world, the tree tops, is reflected in the glass. Just about where her ring finger is, the glass is heavily scratched ... and eventually you realise that this is where years of diamond rings have left their mark. When I saw this, I instantly wanted to know what sort of woman Miller was that she should not only notice this small detail but be so confident as to capture it ... in a picture that years later can still entrance. You want sexiness? That photo has more sexiness than any frame of a girl with a finger in her mouth or a bottle suggestively to her lips.

And here is where so many photographers fail. They photograph not what they know and love and feel passionate about, but what they think they should photograph. They're so afraid to leave anything to our imagination that they give us eager-beaver sexuality. In the process, we are short- changed with vapid, useless photographs. And what a fantastic, incriminating evidence of wasted time bad photos are.

It is unnecessary for me to name the guilty, because their work does that so unequivocally for them. Look for photographs with no soul, easily spotted because they elicit no reaction, trigger no emotions. The Bailey exhibition is the opposite of that, but it makes you realise that, often, photos are actually better reflections of the person behind the lens that those in front of it. Bailey calls photos "controlled accidents", but some are happier accidents than others.

`David Bailey: Birth of the Cool': Barbican, EC2 (0171 638 8891), to 27 June. Lee Miller's `The Exploding Hand' can be viewed by appointment at the V&A print room, SW7 (0171 938 8617).

Robert Winder returns next week.