THE BEST known story of British art in the 1930s is in the grounds outside the National Gallery of Modern Art. A reclining figure, a rock form with holes – Henry Moore, Barbara Hepworth – these are the sculptors, the artists which we remember. But it is not the only story of art in the 1930s, as this new exhibition amply and rather fabulously demonstrates.

There are 58 painters in this large but not unwieldy show, the first-ever exhibition of a “forgotten generation” working in the realist tradition. The realism was not just in their staggering detailed technical attention to the depiction of the world around them, but in their subject matter, from changing technology to the evolving role of women. A diverse grouping – never a movement – these disparate artists flew in the face of abstraction and expressionism to convey their own perceptions of life in the interwar period, often deliberately evasive (yet not entirely dismissive) of the horrors of the war which much of the population had just been through.

And what a hugely surprisingly and eye-opening show it is. The aesthetic is in many ways instantly familiar, for this is partly the art of the iconic 1930s railways posters, of the age of the new leisure pursuit, of fitness and health in the face of austerity and poverty. This is the age when the lido became popular, when swimsuits, so we are told in the blurb next to Harold Williamson’s stylishly posed swimmer, Spray (1939), were made from a new latex fabric, rather than baggy wool.

In similar vein, James Walker Tucker’s Hiking (c.1936), a healthy vista of young women in shorts and what passed, then, for walking shoes, pouring over a map of the Cotswolds, rucksacks and billy cans on their backs. It’s a scene so overflowing with health, cleanliness and a curious freshness of light (which is, in part, down to Tucker’s choice of tempera as medium) that it seems to echo the calls of those such as the Sunlight League, founded in 1922, to “restore sunlight to our malurbanized millions,” to those residing in the dirty, polluted cities which Ruskin had once denounced.

There is much cleaning up of dirty situations in these frequently luminous images, much idealizing of (nonetheless realistic) landscape. Edward Wadsworth’s view, again in egg tempera, of the notorious red light district, Rue Fontaine de Caylus, Marseilles (1924), is a pastel-hued vista of vertiginous clothes lines hiding the dark doorways off the street below.

Darkness is more evident in the portraits of Gerald Leslie Brockhurst, a society painter – society that included Marlene Dietrich and the Duchess of Windsor – whose luminous oils are represented here by Dorette (1933), a striking portrait of the woman who was to become his lover, and By the Hills (1939), a painting so glamorous the word was that the painter had used real lipstick for the lips. Both are painted in front of Italianate backgrounds, reminiscent of Leonardo da Vinci.

Brockhurst, who also worked as a printmaker, was just one of many looking back art historically – to the classical period, to Italy, to the Netherlands – in an attempt to reinvigorate, to mark a sea change from the time and reality of war.

There are many striking portraits here, sometimes of athletes or gymnasts, sometimes of wives, families, evacuees and domestic scenes. Meredith Frampton’s immaculate Woman Reclining has a glossy luminosity, a pared-back classicism emphasized by the simple white dress, the red shoes, the almost complete absence of visible brush strokes.

Further on, there is Bernard Fleetwood Walker’s more tactile, vulnerable and human portrait of evacuees, Children in the Country (1942). And then, subverting but reinforcing the genre, there are Alan Beeton’s curious but striking oils of lay figures posed or left in a chair, doll humans given the scrutiny, as his peers noted, of a Dutch master.

Stanley Spencer is the name most will know from this era of realism, and there are a number of his works here, not least in a room of religious tableaux. These works, by various artists, are all largely transposed to more modern – or contemporary classical (the 1920s equivalent of a theatre director putting everyone in grey suits) – settings, notably Spencer’s unfussy St. Veronica Unmasking Christ (1921).

In a further change in style, the dour brilliance of Winifred Knights (1899 – 1947) whose The Deluge is a masterpiece of balletic, angular movement, an instant sombre rush of figures and supplicant hands, moving in one wave away from the flood which threatens to consume them.

In the final room, harking back to Victoriana in its very traditional tableaux yet capturing the zeitgeist, there is Charles Spencelayh’s stoic First World War veteran, sitting in his lonely parlour on the eve of World War Two, staring into the distance as if the cipher for all the unexpressed fears of all the painters and workers, hikers, debutantes and swimmers of the interwar years. It is an emotive image, quietly capturing the futility, the remembered horror, and placing it right in the heart of the realists’ intricately detailed domestic arena.

True to Life: British Realist Painting in the 1920s and 1930s

Scottish National Gallery of Modern Art (Modern Two), Edinburgh until October 29

www.nationalgalleries.org