Although plenty of artists collaborate, it is very rare for a husband and wife to produce work together throughout their professional careers. Claes Oldenburg and Coosje van Bruggen now operate as a single unit, but before their marriage Oldenburg had already established himself as an outstanding Pop practitioner during the 1960s. Bernd and Hilla Becher, on the other hand, started exhibiting their joint work from the outset, and never looked back.

Bernd met his future wife in 1957. They were both working at the Troost Advertising Agency in Düsseldorf, to support themselves as students at the Staatliche Kunstakademie. He was studying typography and she concentrated on painting. But they soon decided to focus on photography, even though the Kunstakademie did not consider camera-based work important enough to form part of the curriculum.

Undeterred, they devised their own programme, initially using a Rolleiflex and then moving on to a large plate camera. At that time photography was widely considered to be beyond the limits of “fine art.” The Bechers, however, were at the forefront of an emergent determination among young artists to give photographic work the legitimacy it deserved.

Hilla had earlier been apprenticed to Walter Eichgrun, a rigid conservative descended from a family who had served for many years as official photographers at the Prussian Court. Becher had undergone no such training, yet he had used a camera as a young man to record some industrial structures which haunted his imagination. Having grown up in Siegen, the birthplace of Rubens but later a coal-mining Westphalian city overshadowed by an immense blast furnace, he was fascinated by these images. A photograph of a local ironworks reproduced in a local business gazette proved so unforgettable that he decided to draw the structure on site.

At that stage, in the mid1950s, he was studying painting and lithography with Karl Rossing at the Stuttgart Kunstakademie. But Becher made a special journey to the ironworks, and was dismayed when he realised that it was about to be demolished: hence his swift decision to photograph it with a 35mm camera, providing a record that would help him to finish the drawings. Becher was surprised to discover that the photographs were more impressive than his attempts to give the ironworks graphic form.

He and Hilla began collaborating in the late 1950s, concentrating at once on the industrial territory that would be their lifelong preoccupation. The Ruhr Valley, where Becher’s family had worked in the steel and mining industries, was their initial focus. Driving around in a van filled with their own ladders and scaffolding equipment to help them to take photographs from the most effective vantages, they started looking at water towers. Since the cost of colour film was prohibitive, they limited themselves to black-and-white prints. Shot invariably against overcast skies, which provide a neutral backdrop and minimise shadows, the water towers come into their own. They are seen clearly, as if for the first time. This new objectivity was a revelation.

Over the next few years, working largely in the Ruhr district and Holland, the couple – who in 1961 sealed their partnership by marrying in Düsseldorf – photographed pithead towers, coal silos, blast furnaces, lime kilns, coke ovens and oil refineries. They held their first exhibition in 1963 at the Galerie Ruth Nohl in Siegen, where local visitors were doubtless astonished to find industrial images arrayed on the walls in magisterial ranks. The Bechers used the term “typology” to describe these ordered sets of photographs, yet their systematic approach also served to underline the essential strangeness of the structures.

At the end of the decade, a book of their work was given the title Anonymous Sculpture. It reflected the understanding and admiration they received from a new generation of adventurous viewers reared on the stripped, monumental austerity of Minimalism. Carl Andre wrote appreciatively about their work, pointing out in the December 1972 issue of Art-forum that “the theme of variations within limits determined by function is made apparent by the Bechers”.

The same overriding intention lay behind all their work, which embraced half-timbered workers’ houses in South Westphalia as keenly as high-tension electric pylons or preparation plants of coal and iron-ore mines. Andre also pointed out the timeliness of the Bechers’ images, emphasising that “when these structures no longer serve their purpose efficiently they are abandoned”. By underlining their “transient existence”, Andre hinted at the poignancy running through all the Bechers’ work. Even so, neither Bernd nor Hilla attempted to make overt, emotive comments in their art about the vulnerability of its chosen subjects.

In 1972 their growing international stature was recognised by the decision to include them in Documenta 5 at Kassel. By then they had exhibited in locations as wide apart as Los Angeles, the Museum of Modern Art in New York and the Edinburgh Festival. Everywhere they made a singular impact. The documentary aspect of their work was demonstrated by their insistence on recording the sizes, dates and construction details of the structures they photographed. Their modus operandi provoked a great deal of debate, and their detractors often refused to regard them as artists at all. But they maintained that “the question if this is a work of art or not is not very important for us. Probably it is situated in between the established categories. Anyway the audience which is interested in art would be the most open-minded and willing to think about it.”

In Britain they remained little-known until 1972 when Nigel Greenwood, one of the most audacious young dealers in London, gave them a memorable show at his gallery. When the Arts Council organised a larger survey of their images in 1974-75, its director of exhibitions Norbert Lynton argued that “the art world has embraced them as works of art, and the whole punctilious process. . . akin to those of conceptual art”.

That is why this landmark exhibition looked so fresh, stimulating and pertinent when displayed at the ICA in London. Its contents revealed that the Bechers, as well as photographing winding towers in Bochum or the Cévennes, had now visited South Wales to explore collieries in Hirwaun, Pontycwmmer, Treorchy and the Rhondda Valley. And in their exhibition catalogue the Bechers emphasised that “Britain seems to be more conscious of preserving examples of these structures and the need to document them. . . People were immediately sympathetic and did not find our requests curious.” The Bechers were not sure of the reason. They speculated that “perhaps it is because England was the country where the Industrial Revolution started, so the structures have been part of your history for a long time. But it also has to do with the British love of inventors and engineers; people like Brunel, Stephenson and Watt are heroes.”

The Bechers taught at the Düsseldorf Kunstakademie, where Bernd was professor of photography, 1976-96. They exhibited ever more widely, and disseminated their work in a range of books with such matter-of-fact titles as Blast Furnaces (1990), Gas Tanks (1993) and Industrial Façades (1995). At the 1991 Venice Biennale, the sculptural strain in their work was recognised by the Golden Lion judging panel, who gave them the award for sculpture.

Yet the Bechers themselves never presumed to control the viewers’ responses to their work. They once admitted that “we were given the label ‘Anonymous Sculpture’, it is not so important but perhaps it is worth considering. We are interested in how people see; we do not want them to look with our eyes but for themselves.” On the other hand, they knew exactly why they had elected to use a camera as their working tool. “When you look at something”, they explained, “you look at first one detail and then another until your memory builds up a complete picture. You never see anything in detail at once but the camera can do this.” In 2004 they won the Hasselblad Award.

Among Bernd’s many appreciative students were several young artists who today enjoy formidable international success: Andreas Gursky, Candida Hofer, Thomas Ruff and Thomas Struth. They may now have gone far beyond the Bechers in exploring portraiture, urban interiors, landscapes and spaces densely packed with people. But their cool, objective approach still owes an openly declared debt to their teachers’ crucial example – just as the Bechers themselves revived the legacy of earlier German photographers such as August Sander, who had thrived in 1920s Weimar at the height of the Neue Sachlichkeit movement.

Becher is survived by his wife and by their son, Max.

Bernd Becher, photographer, was born on August 20, 1931. He died after heart surgery on June 22, aged 75