August Sander at the Tate Modern

Among Tate Modern’s many achievements to be celebrated as it marks its 10th birthday this month is the integration of photography into the history of 20th-century art. Five new galleries dedicated to the medium, with an emphasis on German contemporaries such as Thomas Struth, Thomas Ruff and Bernd and Hilla Becher are now open; at their core is a superb showcase of the father of modern German photography, August Sander.

With classic German literalness, clarity and a lexicographer’s ambition to categorise, Sander’s “People of the 20th Century” series depicted the types who would “provide a true psychology of our time”: from banker to baker to beggar. “Gentleman Farmer and Wife”, he in shiny suit and gleaming shoes, she in formal black dress, are portly, bourgeois, heavy in tread and thought, proud of the orchard that frames them.

‘Secretary at West German Radio in Cologne’ (1931)

Yet the longer you observe the couple, the more an inexplicable nerviness disturbs their fixed, steady look. The farmer’s brother appears in “Pastry Cook”, also round, solid, firm of gaze, at work in his kitchen with an outsize spoon and tureen. But a second shot shows him as a widower with two skinny ghost-faced small sons: a figure of dignity and dread, trying to hold his place in a fracturing society.

“Disabled Ex-Serviceman”, in a wheelchair at the foot of an impossible staircase, has the same stoic reserve and pristine isolation; so does the sinuous, androgynous smoking woman in “Secretary at West German Radio in Cologne”, and the fur-clad, hawk-eyed “Art Dealer”. All might have walked off Neue Sachlichkeit (New Objectivity) canvases by Otto Dix or Georg Grosz, with whom Sander shares a heightened realism and undercurrent of anxiety, though his subjects are depicted with none of their irony, melodrama or caricature. Instead, whether his subject is a Nazi officer or a Jew, a slick industrialist or a bohemian poet, “he shows them as they would wish to be known”, as essayist Golo Mann observed.

That respect was an act of collusion that, paradoxically, guaranteed the real Sachlichkeit that made Sander the unrivalled anatomist of the Weimar Republic. He believed that when the portraits were shown together, the juxtapositions would make their meaning clear. The formal impartiality did not conceal his political sympathies – his parade of individual difference on equal terms led the Nazis to censor his first book, Face of Our Time; the printing blocks were destroyed in 1936. Among its most potent images is “Working Students”: the four bright-eyed radicals include Sander’s son Erich, who was later imprisoned and died in Nazi captivity. Of the quartet, another was shot in Russia, the third committed suicide; just one survived the war, in hiding.

Almost every image here distils 20th-century Europe in flux and disintegration. The earliest, from summer 1914, is “Young Farmers”, kitted out with hats, jackets and canes, strolling to a Sunday dance – a vision of innocence that now denotes the end of an epoch. Sander loved nature – his landscapes are also shown – and brilliantly evokes the textures of country life: a farmer’s leathery skin, a child’s pram on a patch of grass. His concentration on farmers was criticised as antiquated even in the 1920s; his sense of Zeitgeist, however, was flawless: he reinforces precisely German nostalgia for rural certainty at a time of hyperinflation and record unemployment.

Among metropolitan images, Sander’s masterpiece is “Painter” – it was part of his neutrality to name professions, not individuals – where artist Anton Räderscheidt in dark coat and bowler hat is silhouetted against Cologne’s empty, receding Bismarckstrasse in pale grey morning light. The bizarre, floating effect recalls the dissonances of surrealism, yet “I hate nothing more than sugary photographs with tricks, poses and effects”, Sander said.

Taking a perspective that was neither too close nor too distant, framing his subjects centrally and lighting them with the sharp focus of traditional portraiture, he eschewed the distortion, montage or ingenious viewpoints of avant-garde practitioners such as Moholy-Nagy, Rodchenko or Man Ray.

Pursuing his lifelong project with slow elegance, Sander fixed still, rhythmic, decisive moments that are the opposite of Cartier-Bresson’s darting, graceful ones. The difference is that between Dufy and Beckmann, or Matisse and Kirchner, and Sander’s exposure here adds a fascinating dimension to our understanding of both German art and modernity.

‘Photographic Typologies’, www.tate.org.uk/modern. From May 1