~ Posted by Simon Willis, August 7th 2012

There is a moment in "Another London", the photography exhibition now on at Tate Britain, when past and present hang side by side. It comes courtesy of Bruce Davidson, an American photographer who, like every photographer in the show, captured a foreigner's view of the city. In one picture, two women, both smartly uniform in hats and gloves, haul old-fashioned coach-built prams across a park. Next to it is a picture of a young woman, her hair cropped short, carrying a kitten. The women in the park are from another, starchier era; the woman with the kitten—so individual, with no hint of a uniform—could have been photographed yesterday. The two pictures were shot in the same year, 1960.

The combination is a startling emblem of that decade, but an emblem of the show too, which is a portrait of a city transformed. Much that is shown in the earliest pictures has passed away. In 1937 E.O. Hoppé (born in Germany) photographed "a typical young businessman" at the London Stock Exchange, his unflappable top-hat and tails a world away from the sweat and chaos of the modern trading floor. In 1951 Robert Frank, another American, shot a London street disappearing into the smog, which has itself disappeared from the city. But there are also touches of continuity. Martine Franck, from Belgium, photographed the crowd in Parliament Square for Princess Anne's wedding in November 1973, waiting expectantly in Union Jack hats. It's an image of this summer as much as that winter.

What you don't see much of—oddly, given that this is a show of photographers from elsewhere—is people from overseas. There is not one Indian face, for instance, in seven rooms of photographs, and relatively few people from the Caribbean or Africa. But there are plenty of pearly kings and queens, who leave you feeling that some of these photographers came to London searching out the city's quintessentials and occasionally flirted with its clichés.

But despite its gaps, the show does one thing very well. "In Czech the synonym for 'to photograph' is to immortalise," says Marketa Luskacova, quoted on one wall. I went to the exhibition with my mum and dad, and when they saw Bruce Davidson's shot of a stern bus conductress (1960) the sound of the machine dialling in their fare, followed by a ping, came vividly to mind, as did the old London dialling code on the back of a man's sandwich board—GER 1486, the prefix standing for the Gerard Street exchange in Soho—little details, long gone, on the gallery wall and back in their heads.

Simon Willis is apps editor of Intelligent Life. His recent posts for the Editors' Blog include Late night shots in Arles and Gatsby word for word