AN APPOINTMENT at a portrait photographer's studio in Queen's Road West in 1954 changed a young boy's outlook on the world and gave him a hobby that he was to pursue relentlessly for the next 40 years. H. Kwan Lau had been dragged along to the session by his mother and grandmother. 'In those days it was a fairly regular thing, to go to the photographer's to have one's portrait done,' said Lau from his New York office. 'For the women it was quite a performance, special hairdos were required and clothes and so on. As a 12-year-old, I was bored to tears hanging about waiting for them to finish, so I started looking around and I came across this old album of photographs of Hong Kong. It showed a completely different place from the one I knew and I was fascinated.' The photographs had been taken a century earlier, before even his grandmother was born, and to a small boy the people in the funny hairdos and costumes of 19th century China represented a totally different world from that in which he lived. Lau had to buy that old album. The photographer wanted $55, a lot of money for a child at the time. He emptied his piggy bank: it contained his entire savings of $23, but his father, shrewdly, lent him the rest. Thus began his obsession with searching out old photographs of East Asia which culminates on October 19 when the collection will be auctioned by Christie's in London. It is said to be the finest private collection of photographs of 19th century China and Japan. Lau collected nothing after the 1890s. 'I was always very discriminating,' he said. 'I only bought the very best quality.' The collection of some 2,000 images contains rare photographs of the twilight years of the corrupt and ineffectual Qing dynasty, recording China's Manchu rulers as they crumbled before the might of foreign powers. There are shots of the Yuen Ming Yuen, the old summer palace of the imperial court which was sacked and burned during the second Opium War. And there are controversial photographs of the Boxer Rebellion which reveal extremely rare views inside the Forbidden City. Many of the works, for example a panorama of Shanghai made in 1881 by the photographer Kung Tai, are in mint condition. The 20-frame panorama of the busy port, taken before the Bund was built, stretches more than four metres. India Dhargalkar, Christie's photography specialist, highlights the first lot as being an especially interesting item in a unique collection. The image is of General Ko Lin, the yellow bannerman or cavalry chief of the Manchu court. It is the first known Chinese daguerrotype, taken by Lai Chong in Shanghai in 1852, just 10 years after Daguerre invented the camera in Paris. Lau left Hong Kong in 1959 to study and settle with the rest of his family in North America. As a consultant architect he travelled the world looking up photo dealers who came to know him as a seriously discriminating dealer. One day he came across the earliest known photograph of Tibet, the country which had hidden from the world for centuries. It was taken in 1870 by Francis Friths, who also took the earliest photograph of Egypt's Great Pyramid in 1852. Subsequent research suggests the picture may not be of Tibet but the Qinghai borderlands. Nevertheless, Lau said, 'no one knows how or why he happened to make such an early trip there. There were no darkroom laboratories then. The photographer made his own plates [single shot film] from egg white and silver nitrate. They had to be developed within two hours or else they would be destroyed by heat and humidity.' The collection contains not only the work of relatively well-known visitors to China, such as Italian Felice Beato and Scotsman John Thompson, but also that of the more obscure, sometimes anonymous Chinese photographers. 'We know more about the foreign photographers, their work is better documented and they kept diaries,' Dhargalkar said. 'Early Chinese material is very hard to track and there are only half a dozen people worldwide who have done any research.' There was, for example, a fine photographer in Hong Kong called Afong Lai, whose work is represented in the auction by an 1870s album of photographs of typhoon damage in the young colony. 'We know very little about his work,' Dhargalkar said. Christie's estimates the collection will raise between ?100,000 and ?150,000 (HK$1.2 million and HK$1.8 million) for the Lau family, who are selling because 'we felt we should no longer be responsible for preserving this body of work and that it should be opened up for others to research'. But because such a collection has never been sold before, no one really knows what it will fetch. 'It could be double, even triple that sum,' Lau said.