Photographs. Are they snapshots of history caught on film, records of the past or, depending on the angle and cropping, distorted views of what really happened? George Frew goes to the Pitt Rivers Museum to find out

Photographs. Frozen moments in time, tiny frames of the past, from the family snapshot taken on holiday to the second that the shutter clicked on history in the making. Photographs. Chemically produced impressions of the way we were, faded memories, bromide paper keys capable of unlocking the doors of the past

Elizabeth EdwardsFrom the Deguerrotype to today's digital images, the photograph occupies a unique place in the story of the human race.

And photographs, according to Elizabeth Edwards, curator of the same at the University of Oxford's Pitt Rivers Museum, in Parks Road, are "partial truths." These partial truths form a collection which has always been an integral part of the Pitt Rivers Museum since its foundation in 1884.

The photographs themselves have always been the reason for the collection's existence, rather than ephemeral sideshows stocked around an object, like bridesmaids destined never to be brides.

The photographic collection has always been steeped in seriousness - it's an academic research collection, as opposed to a mere picture library.

In controlled conditions, the anthropological evidence - some 120,000 images from a total of around 200,000 objects including lantern slides, prints and negatives - is catalogued and filed. Culture diaries exposed on film.

Elizabeth Edwards is an historian by training and an enthusiast by nature. "Cross culturally," she explains, "pictures can reach where other things cannot. But we don't just hand over our photographs to just anyone - we're here to help the people who have a right to know about their culture, who need to have a deeper knowledge of their history."

That knowledge has been amassed over the years and includes visual contributions as diverse as Morris Dancers and missionaries in the Pacific.

"These pictures can teach us," says Elizabeth. "They are here to think with, historical documents of the first order. They differ from, say, Press photography because anthropological photography comes out of a profound understanding of a culture - the camera is not just an aide-memoire, whereas Press photography is a visual incision of the moment.

"But anthropology has been well served by photography and we work with people who know what it is they are looking at. I'd like to think that we have a collection here capable of historical readings.

"We try to answer questions and facilitate relationships at a deep level. Helping people discover their ancestrors is a humbling experience."

The pictures themselves reach out over the years and across the oceans of the world. Images of Irish crofters sit comfortably beside those of the peoples of the Pacific - especially in the photographs of Captain William Acland, son of Sir Henry and brother of Angelina, of the Aclands of Broad Street, Oxford, and the hospital in the city's Banbury Road.

Captain Acland was a career sailor whose faithfully recorded images form part of the Pitt Rivers' collection. And it is a collection that is still active. "Especially," Elizabeth points out, "the 1920s to1930s inter-war period." Who would have thought that the colonial photograph album's of the Empire's tea planters were destined to become one of the cornerstones of anthopological photography?

"We are also active in working with indigenous groups," Elizabeth adds. "Musueums have to tread a complex tightrope, one of mutual respect and collaboration. People who use the collection are delighted that their history is treated with respect and we try never, ever to misuse or misappropriate other people's history."

The museum is currently developing a www picture gallery, as a specimen of what's in the collection itself. On the sort of budget on which the term 'shoestring' would appear lavish, they have already developed CD-Roms for the reservation schools of Native Americans.

Additionally, Elizabeth Edwards has just published Raw Histories, an academic work in which she argues that the 'raw' quality of photographs can, instead of hindering historical understanding of the subjects, instead open up new perspectives on the subject. "Photographs are a picture on the world - but whose view?" she asks.

Photographs shape our understanding of the past and present. Photographs can show alternative viewpoints.

And, in the end, photography such as the Pitt Rivers' collection proves that anthropology and art can climb into bed together without one of them deeply regretting it in the morning.