'Mostly Unseen' presents a selection of photographs taken by David Goldblatt over the past five decades. At times, it is a show of subtle and understated beauty. Divided into five components, it includes 18 classic studies of an impoverished white community in the Karoo, presented under the section heading 'Die Hel'. There are also four landscape studies, three beautifully executed portraits from 1972, 13 recent colour works and three vintage District Six prints on offer.

In his 'Die Hel' series, the dignity with which Goldblatt portrays his subjects certainly places his work a few notches above that of Roger Ballen. Shot in 1966/7, the series explores Goldblatt's key areas of interest: architectural structure (The Mostert House), landscape (The Cordiers Go Visiting) and portraiture (An Old Lady Who Is Waiting To Die). The series is imbued with a sparseness typical of Pauline Smith's Karoo stories. Although insularity is its chief strength, it is also its weakness. This might explain why so few of these pieces (only one) were marked sold.

By contrast, three vintage 1966 District Six prints had the punters excited. Documenting a place that has now lapsed into history and invisibility, the portraits evoke the humanity that once pervaded a spot that is now Cape Town's missing front tooth. Possibly it is their archival value that defines their appeal, but judged against work he was shooting a mere six years later, these are hardly groundbreaking works.

This is particularly evident when comparing the District Six series with the three portraits of youthful black subjects Goldblatt shot in 1972. New Recruit, Fanakalo School, Hartebeesfontein demonstrates Goldblatt's consummate craftsmanship as a photographer. The image shows a young recruit sitting on a white washed stonewall kitted out in a variety of safety paraphernalia. A dignified and studied portrait of an individual, the photograph draws its strength from the interplay between what is denoted and connoted. This fresh-faced youth is after all simply the cheap brawn that powers the mining industry.

As is so often the case with a Goldblatt image, the outside world is rarely brought to bear in a direct way in his work. The disgraces and dilemmas that mark South African history are simply the context framing each of his photographs. Be it Koot Nel in his voorkammer, or the young shop assistant from Orlando West, Goldblatt allows his subjects their own voices. This skill has gifted his work with a unique sensitivity, for the land, its people, and its structures.

Goldblatt has not lost this sensitivity in his transition from black and white to colour. In works such as Playground, Barnato Park High School and Newtown Squatter Camp he offers beautifully textured appraisals of urban Johannesburg, unflinching views of its highs and lows. Colour it would appear has only enhanced his gift for describing everyday life. Among the most striking of his new works is Advertisement on the base of the Hillbrow Tower, a close-up image of an ad hoc notice board offering a diverse range of private accommodation, from lockable bedrooms to sitting room spaces.

Taking the inquiry elicited by this particular image one step further, he also presents a study of Nkosiyabo Ndlovu's subdivided sitting room. Although absent from the image, the photographer Ndlovu does appear in the image by default. Suspended over a double bed shared by father, mother and child in Flat 305 Leopold Heights on the corner of Bok and Claim Streets, Hillbrow, is a large colour image of Knosiyabo. The image is a consummate example of what Chris Killip, in his essay 'A Photographer's Life', describes as Goldblatt's repeated, stubborn, even uncomfortable questioning of photography's inadequacies.

Viewed as a whole, 'Mostly Unseen' is a quirky show to say the least. It could easily pass for an accomplished mini mini-retrospective celebrating the talent of an individual not quite ready to rest on his laurels. Admittedly not all the photographs carry sufficient weight, which might explain why they are still mostly unseen at this late stage in the photographer's career. But then again other forces frame the show: Goldblatt is due to appear at Documenta11. Given the stratospheric rise of William Kentridge following his appearance on Documenta X, the message quite simply is to get in early before Goldblatt's work suddenly commands widespread international recognition, and pricing.