WHEN the artist Paul Nash published his gazetteer to Dorset in 1935 as one of the first Shell Guides, he dedicated it "to all those Courageous Enemies of 'Development' to whom we owe what is left of England". Edwin Smith (1912-71) was one of the photographers invited by John Betjeman and John Piper to illustrate the second edition (1966).

When I first visited Sherborne Abbey as a schoolboy, the great fan vault was already familiar to me from what proves to be one of Smith's richly evocative black and white photographs. Now I find that his, too, is the photograph of Gold Hill in Shaftesbury, the only hill town in Dorset, in which a solitary working man walks down the deserted street.

For the same volume, he also photographed Milton Abbas and a four-storey island housing block in Weymouth, although most of the photographs were taken by Piper. Both men sought out the less familiar and unremarkable, and were as much at ease photographing great churches as smallholdings.

Smith had trained as an architect, but in the mid-1930s he turned almost exclusively to photography. He left his wife in 1943 for the writer Olive Cook, a neighbour who became his companion, and with whom he worked for Hutchinson's regular Christmas publication of The Saturday Book.

The current exhibition shows some 100 of his photographs in a broadly chronological sequence from 1935 when he began with fashion photographs for Vogue. One is of a behatted lady languorously dripping a cigarette from her hand in a Mayfair garden, and in another an overcoated commuter stands centre stage on Kentish Town platform. An enigmatic face peers out from a reflection amid a wall of hats in a milliner's display window, incomprehensibly entitled a hairdresser's by the curators.

The Second World War changed for ever the face of much of Britain, and led to a debate throughout the 1950s and 1960s, carried on thereafter by town planners, about how to develop the same landscapes earlier commemorated by Nash. Smith's black-and-white photographs celebrate the rapid changes in infrastructure and in social mobility of the post-war years, prompted, I imagine, by the wartime publication of Recording Britain.

The exhibition is timely as our nation debates its own immediate future and the nature of a united kingdom; for Smith travelled widely at home. Although he visited Sicily in 1954, and his 1965 volume of The Wonders of Italy is open at a page showing Bari Cathedral, he most often tended to stay in the North Atlantic Archipelago. One of the last displays is of photographs of houses and churches in Ireland before the Troubles.

In 1936, he was invited by the Tory MP Sir Arnold Wilson to photograph the miners, fishermen, and shipbuilders of the north-east. The resulting photographs include one of two teenage miners at Ashington colliery, and another of four jacketed workers seated on the stoop at Newcastle Guildhall, behind whom is chalked up the graffito "Jesus died for you". Early morning captures fishermen at North Shields, their outlined figures silhouetted at work.

Wilson, who was the third MP to die on active service, at Dunkirk, had been the former acting Civil Commissioner of Mesopotamia who persuaded the Western Powers to accept the Arab name (Iraq) for the territory, and who was instrumental in creating the kingdom of Syria. He was outspoken, and had been publicly denounced for his admiration of the leaders of the Third Reich.

Whether Smith shared his right-wing views or not, his photographs commented powerfully on a broken nation. The shadow in these early photographs is the long one cast by the Jarrow marchers and the dismal world of the 1930s, a far cry from the fashion model in the garden at 72 Brook Street, Mayfair.

Smith largely contented himself with the domestic details of ecclesiastical pictures, and is, perhaps, seen at his best in the photographs that were reproduced in photogravure. Although St Lawrence's, Didmarton, in Gloucestershire, is famous for its untouched 18th-century box pews, Smith chose to photograph a cramped corner of the vestry when he visited in the early 1960s. A steep ladder runs up to the bell tower above, and a short surplice hangs, half forgotten, from a nail off one of the treads.

In the parish church of Hinton St George, he captures one of the Poulett family wall memorials as seen through an arch over the re-used effigy of an earlier member of Sir Amyas's family, as if prying into their dead world. St John the Evangelist's, Shobdon (1959), is a former priory church that, Nikolaus Pevsner noted, had been "converted into an eye-catcher" in 1752-56. But Smith deliberately eschews this rural display of Strawberry Hill Gothick in Herefordshire, taking us instead into the vestry, with its jugs of flowers sitting on a coffin trestle.

The south-aisle perpendicular windows at St Andrew's, Westhall (Suffolk), stream with light, illuminating the poppyhead pew-ends, but obscuring the wall decoration.

Smith evokes the "bare ruin'd choirs" of England and, indeed, Scotland; Sweetheart Abbey and the Chapel Royal at Falkirk are the most enigmatically satisfying of his compositions. More than once, in this deeply moving exhibition, I found myself on a pilgrimage through the Divine Landscapes that our own Ronald Blythe captured back in 1986, using some of Smith's photographs.

"Ordinary Beauty: The Photography of Edwin Smith" is at RIBA, 66 Portland Place, London W1, until 6 December. Open Monday to Saturday, 10 a.m.-5 p.m. Free guided tours every Friday at 12.30 p.m.

Phone 020 7580 5533.

www.architecture.com