A critical eye

'Painting and sculpture, literature, poetry and theatre were very closely observed by the Stasi," says Gundula Schulze Eldowy, an artist and photographer who was based in east Berlin in the 70s and 80s. "Photography less so, and that was simply because they didn't perceive it as an art form." Photography, in other words, could get away with a critique of the repressive communist system that was largely denied to the other art forms.

That relative freedom is what curator Matthew Shaul calls the "theoretical nub" of his exhibition of photography from East Germany, Do Not Refreeze, which is touring the UK. Happily for photographers, the East German elite were artistic snobs with what Shaul calls " a backward-looking way of seeing photography". Photographers had a degree of licence denied to painters, sculptors and artists, and Shaul believes they used it to create a powerful body of work that bears comparison with the documentary photography of Cartier-Bresson and Robert Frank.

That is a large claim, but he has unearthed a group of documentarists and younger art-based photographers little known in the west whose work fills in a missing chapter in the cultural history of the German Democratic Republic (GDR). Shaul's interest in frozen-out photographers such as Arno Fischer, Ursula Arnold, Erasmus Schröter, Sibylle Bergemann, Evelyn Richter and Gundula Schulze Eldowy was triggered by an exhibition in Berlin in 2003 called Art in the GDR. "Mostly it was paintings of enthusiastic peasants," he says, "but in the last room were these wonderful photographs."

Shaul argues that the authorities in East Germany failed to understand what was being expressed in many of the photographs. "Often the photographers were careful not to add a title beyond a place and date, because socialist ideology was very hung up on definitions. In effect, what they did was generate a visual language which was unreadable to the organs of state power but readable to the general public."

Thus Richter's beautifully composed Receptionist in Town Hall 1975 contains a coded message about a woman imprisoned by the state. "What Richter was trying to do with this and many of her other pictures," says Shaul, "was to communicate between the lines. She was trying to emphasise the way in which people in the GDR were enclosed and expected to give reverence to the communist party.

Behind that woman is a picture of Erich Honecker [East Germany's head of state in the 1970s and 80s], displayed as you would display a religious icon. Another photograph, Entrance to a Convalescent Home 1986, shows a picture of Lenin preaching to revolutionaries. The idea is to use a picture within a picture to present an ideology that had once been dynamic as something that, by the mid-80s, had become tatty and careworn."

Schröter's photograph of a petrol station, called simply Altenburg 1985, includes a faded ad slogan for a type of oil that hadn't been available to East Germans for 40 years. Yet the photograph has a Hopperesque lyricism too. "Schröter had applied for an exit visa," explains Shaul, "and knew he would be leaving. In this series of pictures he was saying his farewell."

Shaul says these documentarists were highly sympathetic photographers of children, and Arnold's lost-looking little boy clutching a balloon bears out his point. The photograph, entitled May 1st, Berlin 1965, is another where the true meaning seems to have evaded the cultural commissars. Here, on this most resonant of celebratory dates, is a forlorn boy and lots of grim-faced adults. "There are balloons every-where," says Shaul, "and everyone should be excited and cheerful. But instead everyone looks sad." He quotes Arnold as remarking that while "the authorities wanted enthusiasm and propaganda, I wanted to present the world on my own terms."

Gundula Schulze Eldowy's photograph of a pair of elderly hands touching two portraits of her dead sons is taken from a series called Berlin On A Dog's Night, shot in central Berlin in the late 1970s. "She was trying to convey the realities of life in a community that, 40 years after the final Soviet assault on Berlin, was still completely traumatised," says Shaul.

After the wall came down in 1989 some of these photographers never again recaptured the spark of their pre-liberation work. "Some have made successful careers in the reunited Germany," says Shaul, "but others have been bereft and their work is a pale shadow of what they did under communism. They needed to push against the wall of state censorship, which defined and nurtured their work; they needed to find chinks in the communist armour, niches in which to express themselves".

· Do Not Refreeze is at the Focal Point Gallery, Southend, until March 8, and at the Wolverhampton Art Gallery from May 10 until June 28.