An example of light imitating art

An exhibition at the Tate in Liverpool puts photography firmly in the category of art. Geraldine Norman judges the criteria

WHEN is a photograph a work of art, and when is it not? Every individual has a different answer. Curiously, it was quite acceptable to consider photography an art form in the 19th century, when photographers like Julia Margaret Cameron took Pre-Raphaelite pictures, but once the technology was simplified to the point where everyone could use a camera, photography came to be regarded as a craft. The national collection of photography is at the Victoria & Albert Museum. The curators are supposed to collect photography per se, without worrying about whether it is art. Presumably they are a little uncertain about the genre, since their vast photographic collection is rarely exhibited.

The inclusion of photographs in the Tate Gallery collection demonstrates that photography is again becoming accepted as an art form. A new exhibition at the Tate in Liverpool, called "Witness", reveals what they have been buying. It is the first exhibition the Tate has mounted of photographs from its own collection, and is a fascinating reflection of what informed connoisseurs regard as art. The Tate only buys photographs when the curators are collectively convinced that art is what they are dealing with.

The exhibition is a perfect starting point for entering the "When is photography art?" debate. The Tate's main criterion proves to be a fairly simple one: that the photographers themselves believe they are making art. The end product they are aiming at should not be a book or a magazine illustration, but a physical object that can be mounted in a gallery. It must be the kind of photograph that gets sold through art dealers.

"Witness" includes the work of Paul Graham from the Anthony Reynolds Gallery, and Hiroshi Sugimoto from White Cube - two of London's sharpest contemporary art galleries. There are also works by Craigie Horsfied and Tim Head, who are both represented by the Frith Street Gallery, founded six years ago by Jane Hamlyn (the daughter of publisher Paul Hamlyn) to specialise in avant-garde works of art on paper, though she has now branched out into other media.

Also in evidence is Hannah Collins, launched by Maureen Paley's Hackney-based Interim Art but now represented by the New York dealer Leo Castelli, the legendary talent spotter who discovered Jasper Johns, Robert Rauschenberg and most of the leading New York artists of the 1950s and 1960s. Collins is one of the very few photographic artists represented by Castelli.

There is also Thomas Struth, a German artist represented by the Marian Goodman Gallery in New York and, of course, his fellow Dusseldorfer, Andreas Gursky. He is represented worldwide by Monica Spruth in Cologne and in England by Victoria Miro - the only "cutting edge" gallery in Cork Street. Until 28 August, visitors to Liverpool will also be able to catch a separate exhibition of photographs by Gursky; two were bought by the Tate earlier this year for DM20,000 (about pounds 10,000) each.

The Tate can't be faulted on picking photographers who regard themselves as artists - and are so regarded by the dealers who make waves in the contemporary art world. These are all very hot artists - this year - and all joined the collection in the 1990s. The exhibition also contains a few 1980s purchases. These don't hang with the new lot, but they do serve as a reminder that the Tate has been buying photographic art for 20 years or so - and that this is a selection, not a comprehensive showing. The images were chosen to highlight what is happening now - and, visually, it is an intriguing story.

The inclusion of two pioneers, Bernhard and Hilla Becher, now both in their sixties, provides a springboard for understanding the newcomers. Gursky and Struth were pupils of the Bechers at the Staatliche Kunstakademie in Dusseldorf. The Bechers were the first contemporary photographers wholly accepted as making fine art. They are of the Minimalist generation. Just as Carl Andre was given to lining up bricks - the pile that caused such a furore at the Tate, for instance - the Bechers line up photos in three- by-three blocks mounted on board. Their reputation is now so established that Sotheby's and Christie's include their work in contemporary art sales; the auction price record for their work stands at $42,900.

The Bechers have compiled an archive of black-and-white photographs of old industrial buildings and plant whose useful life has ended. Sometimes their photographs were taken only hours before buildings were knocked down. These are arranged in serried ranks, always combining buildings that are visually similar but on closer inspection distinct. The young curator of the Liverpool exhibition, Fiona Bradley, points out that their work teaches the viewer to look. The first impact is of rather fascinating archaic machinery; then, quite instinctively, the eye begins to seek out the differences between the photographs. The mind runs along behind, thinking about the way these buildings must have been used by human beings.

The 1990s photographic artists follow on from the Bechers, in that they too make accurate and beautifully crafted records of the real world. Again, to enjoy what they are doing, the eye must lead the mind. But where the Bechers, in true Minimalist style, make images that contain no comment, the 1990s artists explore the mystery and human drama of everyday reality.

Gursky will photograph an extensive landscape in which human figures the size of ants form patterns - the kind an abstractionist would favour for their beauty. The eye follows the pattern, and the mind works on what it felt like to be there. Alternatively, he photographs complex interiors - a textile factory, or the Tokyo stock exchange - where again man and his environment make patterns, triggering the viewer's mind to imagine the experience of being there. He produces large-format colour images in editions of five and, says dealer Victoria Miro, they tend to sell out fast. The images the Tate has bought, Paris Montparnasse and Thebes West, are two of the most popular. Average prices have risen, Miro says, from DM12,000 to DM18,000 (roughly pounds 9,000) since she last gave Gursky a London exhibition in 1992.

Thomas Struth, whose work fetches similar prices, makes large colour photographs of the interiors of art galleries. By photographing the way visitors are looking at the pictures, he manages to echo the poses and movement in the paintings themselves. The mind, following the eye, interprets how the familiar figures in the foreground are feeling, then moves back into the Old Masters on the walls and recognises the same body language.

Paul Graham, a British artist who made his name in the 1980s with a series of photographs of Northern Ireland called Troubled Land, uses a similar colour format in pursuit of much more aggressive political or psychological levels of meaning. A brilliant series of Television Portraits is on show in Liverpool, each of them portraying an individual wholly caught up in his or her relationship with the medium, from a little boy with his nappy slipping who stands on a sofa clutching a TV remote control, to a Japanese girl with her face lit by the screen. They sell at pounds 2,500 each (in editions of five or 11).

Two other British artists, Hannah Collins and Craigie Horsfield, make very large works in black-and-white. Collins's In the Course of Time depicts the old cemetery in Warsaw in autumn, the broken and tumbled monuments covered in a drift of leaves. It is 9ft high and 16ft wide, and is mounted on oil linen so that it can be rolled up. It is a physical object, not just a photograph. Despite the grainy, grey texture of the picture, you feel you are walking into the world Collins has photographed.

Horsfield also heightens the viewer's awareness with grainy black-and- white on an imposing scale. He is represented by a naked woman turning her back to the viewer in a gesture that consciously echoes the Renaissance artist Masaccio's mural of Adam and Eve. It is 6ft high. Collins and Horsfield both make one-off photographic works, not editions; works on the scale of the Liverpool exhibits would cost around $25,000 (pounds 16,000) and pounds 7,000 respectively if you applied to their dealers.

The other black-and-white genius of the show is Japanese photographer Hiroshi Sugimoto. His format is more conventional - framed images 2ft wide - but there is nothing conventional about his approach, which combines Japanese Zen vision with American consumerism. The Tate has photographs of the sea reduced to mist and ripple, and photographs of American drive- in cinemas taken with an exposure that lasted the entire length of the film - the screen comes out blank and lights the surrounding trees, while passing aircraft make patterns in the sky. His images cost pounds 2,500 from White Cube (in editions of five).

The overall impact of the show is extremely powerful. The camera has been used to reveal levels of psychological, spiritual, political and aesthetic value that underlie the material world of today. In other words, it has been used as a tool for making art in just the same way as a painter's brush or a sculptor's chisel.

! 'Witness' is at the Tate Gallery, Albert Dock, Liverpool until 2 January 1996. The gallery is also showing photographs by the German artist Andreas Gursky until 28 August this year.