ART MARKET / The image of our times: Contemporary photography comes of age with an exhibition at the Saatchi Gallery. An auction in aid of two royal charities means it is big on the social scene too, says Geraldine Norman

A TABLE for 10 at the dinner being given tomorrow night at Charles Saatchi's art gallery in St John's Wood, north London, costs pounds 1,500. You don't have to be a genius to realise that no one is paying that kind of money just to get a preview of the photography exhibition, 'A Positive View', which the dinner is ostensibly celebrating, while at the same time raising money for two charities. The exhibition is open to the public, free, from Wednesday.

The 500 guests will be turning up to be seen by each other at a significant social event, organised by Lady Palumbo and Lady Rayne, two of Princess Diana's closest advisers, in 'dear Charles's' gallery. Princess Diana is also the patron of both the charities. It is going to be a big social scene - but that should not be allowed to overshadow the exhibition itself.

The show, which is sponsored by Vogue, is billed as an overview of contemporary photography. It contains some 200 photographs, mainly taken over the last five years, about half of them in colour and several in very large format: they go up to 10ft or so. It cannot be described as a survey - the selection is too random and a bit over-Vogued - but the show is spectacular, unusual in presenting photography as 'art' in an art gallery, and it includes some great prints.

It is essentially a charity auction which has turned into an exhibition. The showing at the Saatchi Gallery runs from 14-30 September. On 3 October, the photographs will be moved to Bond Street and go on exhibition at Sotheby's for three days; at 7.30pm on 5 October, roughly 150 will be auctioned. Charity auctions are notorious for providing the opportunity to buy good art cheap; the wealthy do-gooders who make up most of the audience are not generally connoisseurs.

The method of selecting the photographs was very odd. First, some 200 leading photographers were asked if they would contribute two prints to a charity auction. The organisers had not bargained for the generosity of the response; they ended up with 400 works from 14 countries. Then Sotheby's pointed out that you could not have more than 150 lots in a charity sale, otherwise it would go on too long and the patrons would get fed-up and leave. The donations were vetted and 250 rejected - which led some photographers to take offence.

Then it was decided that the exhibition needed some extra highlights. So Charles Saatchi agreed to lend some works by famous 'artist' photographers from his own collection: Cindy Sherman, for instance, the American who dresses up and photographs herself in different roles; and Andres Serrano, who photographed a crucifix in a bottle of urine and caused a rumpus that reached right up to the US Senate. Photo pieces by David Hockney and Jeff Koons have been borrowed from commercial galleries and some older photographs are on loan from the Vogue archive, including the spectacular picture by John Deakin of a young Francis Bacon holding half a sheep's carcass in each hand.

The sale will be a major event. Sotheby's has cancelled its autumn photography auction so as not to overload the market. Lord Snowdon has given two great images: a study of the sculptor Eduard Paolozzi's hand made in 1988; and a 1992 picture of the enfant terrible of the art world, Damien Hirst, sitting naked in a fish tank (estimates pounds 800- pounds 1,600).

Another royal associate, Koo Stark, has contributed two 1990 nipple studies, The Scream and A Right Tit, which make up in sensation what they lack in artistic finesse ( pounds 500- pounds 1,000). Annie Leibovitz, currently one of the most fanatically admired of all celebrity photographers, has sent in a photograph of Bruce Springsteen at the wheel of his car at Asbury Park, New Jersey, in 1987 ( pounds 1,000- pounds 2,000).

Serious photography buffs will be more excited by Bill Brandt's two nude studies of 1952 and 1956 - both later prints, but signed ( pounds 1,000- pounds 2,000 and pounds 2,000- pounds 4,000 respectively); Sebastiao Salgado's famous view of a Brazilian gold mine, Serra Pelada, 1986 ( pounds 2,000- pounds 4,000); an Eve Arnold Marilyn ( pounds 1,600- pounds 3,000) and her celebrated study, Horse Training for the Militia, Inner Mongolia ( pounds 800- pounds 1,800); not to mention two great images by Jacques-Henri Lartigue (1896-1986) which date from 1908 and 1910 ( pounds 2,000- pounds 4,000).

Heaven knows why this French painter- photographer should be included in a contemporary show; he was given a camera at the age of nine and snapped his family and friends throughout his life. The 1908 photograph shows a man in a boater jumping four garden chairs set in a line and is entitled Oleo Van Weers, Notre Champion du Saut Chaises; the 1910 print shows various friends trying to fly an early glider.

Great works that genuinely belong to recent times include two huge 1994 landscapes by Paul Wakefield: Colorado Plateau USA ( pounds 400- pounds 800). Photographed at sunrise, the land has turned into abstract patterns in blazing shades of red and gold. Roger Mayne's Man and Shop Window, Rue de Reaumur, Paris, 1993 shows a businessman unwittingly advancing on a window full of naked mannequins ( pounds 400- pounds 800).

Then there are some remarkable unknowns that the exhibition has brought to light. Two young Russians have contributed stunners: Sergei Borisov's Flying of 1988 catches a man jumping off a bridge in the centre of Moscow ( pounds 200- pounds 400); while Vladimir Smirnov's series of three photographs entitled Old Walls shows the desecrated interior of a church covered in graffiti (not for sale).

Anna Fox, a 33-year-old Londoner, is the most exciting British discovery. The organisers were so impressed by the two prints she sent in that they asked for four more. The six big colour prints belong to the post-modern, daylight- flash school of photography, and depict details of a society wedding. A combination of coloured silks, orange blossom and safety pins, they could have been taken on the set of Four Weddings and a Funeral ( pounds 1,200- pounds 2,400 each).

The event was masterminded by Andrew Page, a young advertising executive whose hobbies include photography and raising money for charity. His wife and daughter work with the Chicken Shed Theatre Company, a charity that mounts productions in which disabled people work with able-bodied professionals. Page put the idea of a major photography exhibition and sale to the Chicken Shed board - chairman Lord Palumbo, president Lady Rayne. They liked the scheme, suggested that a major sponsor was needed, and enrolled Vogue, which has been commissioning work from the world's top photographers for more than half a century.

Vogue said the exhibition must be held in a top location and prevailed on Charles Saatchi and Sotheby's. They also demanded that a national charity should share the proceeds; Chicken Shed chose to share with DEBRA (Dystrophic Epidermolysis Bullosa Research Association), which also has the Princess of Wales as patron. Saatchi was anxious that artistic standards should be maintained and asked the eminent art writer David Sylvester to hang the show. Sylvester said he must have a photography expert to advise him; the dealer Zelda Cheatle was signed up to help him.

The exhibition will give collecting photographs a social seal of approval it has never had before. With the inclusion of photographic works by well-known artists such as Hockney and Koons, it will also give visitors an opportunity to decide for themselves where the line should be drawn between photography and art. 'I think they will see that there is no line,' says Philippe Garner, Sotheby's photography expert. 'All the photographs in this show are works of art.'

Garner has a clear view of the market interest of the event. Most of the works are too new to have an established resale value. 'It's a learning exercise,' he says. 'It will show us what's been done very recently in the photographic field and how bidders respond to it. Photographs of this period are what we'll be selling at Sotheby's in a decade's time.'

'A Positive View' opens to the public at the Saatchi Gallery, 98a Boundary Lane, London NW8 0RH, on 14 September.