A girl looking to her left, her fingers loosely on her mouth, gazing downwards with a half smile, light filtering through behind her. This is the opening image, a vintage gelatin silver print known as Untitled 1973-4, of William Eggleston’s exhibition at The National Portrait Gallery, fittingly easing visitors into Eggleston’s universe of supreme indifference. For while he is known as one of the pioneers of colour photography as an art form, it is the ordinariness underpinning his portraits — faces often glancing uncertainly outside the frame or looking at him unengaged, bemused — that set him apart as one of the most original storytellers (or rather anti-storytellers) of postwar America.

The exhibition begins with a brief immersion in the initial decades he spent on experimenting with black and white photography before plunging us into rooms of large-scale kaleidoscopic prints. The tension between radiant hues and the lack of drama of angle and lighting establishes Eggleston’s visual language. It was formed in part after the oracular advice of one of his University of Mississippi instructors, Tom Young who urged Eggleston to apply equal intensity to all things, especially those that bored or repelled him. This is often understood as the catalyst behind Eggleston’s self-defined ‘democratic’ style, which encompasses a range of subjects: from close family members and friends shot in his hometown of Memphis to strangers immortalized in his cross-country Nightclub Portrait Series, taken with a 5x7” view camera and portable light setup.

Full of striking moments of intimacy, caught by an unassuming camera, the exhibition also features glimpses of an alternative, unwritten history of the seventies. There is a Dennis Hopper portrait from a trip Eggleston and gonzo curator Walter Hopps made to Hopper’s log cabin retreat in Taos, New Mexico, about which he writes: “we shot guns and took pictures and laughed a lot about the state of the union.” Bringing to mind Barbara Loden’s recently restored feminist classic Wanda (1970), Eggleston’s portraits carry that sense of pessimism and drift that still looks obstinately forward.

There are also glimpses of hidden romantic histories, adding a narrative layer to Eggleston’s surface of disengagement. Untitled 1974 depicts the artist’s cousin Lisa Aldridge comforting Karen Chatham, who lies defeated on a sofa after being rejected by charismatic musician Alex Chilton. “Not long after,” the caption informs us, “Aldridge would start dating Chilton herself,” before elaborating that their union did not last. Luckily, Eggleston’s stolen moments do.

William Eggleston Portraits is at The National Portrait Gallery, from 21st July — 23rd October 2016.