William Eggleston Portraits, National Portrait Gallery

American photographer William Eggleston is famous for dedicating himself to colour photography at a time when it was still considered kitsch – acceptable for wedding and Christening photos, but not much else. The best known example of his embrace of colour is a 1973 photo of a red light bulb hanging from a red ceiling, a picture devoid of subject matter beyond redness and the associations it triggers.

You could almost say the same of a photograph he took the following year of a young woman at a fast food counter in Biloxi, Mississippi (main picture). We see her from the side waiting expectantly for her order, oblivious of the camera. Cascading over her shoulders, her red hair hides most of her face. Glowing in the evening light, it looks almost on fire compared with her pale skin, oatmeal dress and the beige counter on which she is leaning.

Of The Red Ceiling, Eggleston said, “it's like it's red blood that is wet on the wall. The photograph was like a Bach exercise for me because I knew that red was the most difficult color to work with. A little red is usually enough, but to work with an entire surface was a challenge. It was hard to do. I don't know of any totally red pictures, except in advertising.”

If the challenge of the ceiling was a formal one, what might be said of Untitled? Again the pleasure is visual; the girl’s auburn hair sets this ordinary scene alight with its fiery undulations. There’s no storyline or emotional engagement – just the delight of beauty spotted in banal circumstances. 

Eggleston claims to photograph a person in the same way he does a parking lot. “I had this notion of what I called a democratic way of looking around, that nothing was more or less important”, he has said. “I’ve never been a bit interested in the fact that this was a picture of a blues musician or a street corner or something... I just take the picture.” 

For most people, “just taking the picture” would result in tedious clichés, but Eggleston has an uncanny knack of spotting those sublime moments when random elements cohere to make the ordinary seem strange or beautiful. Ironically, its when he takes what might be described as traditional portraits – isolating a subject and focusing in on his or her face – that the results tend to be unexceptional. 

Instead of intimate encounters, he specialises in treating everyone as a stranger. Even when the sitter is known to him, his pictures of people remain Untitled, because his interest lies not in a person’s individual identity so much as their place in the world. The most memorable of his superb images are of people in an environment; and something about the mise en scene triggers one’s curiosity and arouses one’s empathy.

In Untitled, 1965 (Memphis, Tennessee) (pictured above right), the important detail is the golden light catching the boy’s blond quiff, face, shirt and arm as he shunts a line of shopping trollies through a supermarket door with great concentration. Behind him, out of focus, is an approaching shopper. She has a walk-on role, except that in the shadows cast on the supermarket wall, the roles are reversed. She appears closer and dwarves his hunched form. The joke is that their shadows fit together as neatly as jigsaw pieces.  

The comedy is always visual. Untitled, 1965-8 (Memphis, Tennessee) features two people sitting opposite one another on the green banquettes of a diner. We are positioned behind the woman in such a way that, cresting like a wave, her enormous French twist blots out her companion’s face. We can glean nothing of their interaction except from their hands and elegantly held cigarettes.

Devoe Money (pictured above) sits hunched on a grounded swing; her slight figure seems hemmed in by the busy patterning of her dress, the cushions, the trellis behind, the surrounding bushes and the fallen leaves. Everything in the picture is in decay; entropy reigns.

By contrast, the young black woman walking towards us across an apparently endless plane near Minter City and Glendora, Mississippi looks lost in space. Her lime-green dress echoes the grasses blowing at her feet, while her headscarf matches the puffy clouds. Standing beside a strip of concrete road almost at the vanishing point of the composition, she forms a pivotal link between sky and ground. What, though, is she doing on foot in the middle of nowhere? 

A gathering storm creates the strangely intense atmosphere of Eggleston’s 1973 photograph of his son, William. Dressed in an oddly shaped red cardigan that makes his arms look as if they are dangling, the young boy seems hunched against the wind. Behind him is a line of telegraph poles from which his body appears to be suspended, like a hanged man. 

Eggleston’s best photographs are decidedly cinematic. A narrative seems about to unfold and the outcome is uncertain. A photo of two men standing on dead leaves, beside a white car with its doors open (pictured below Untitled 1969-70 in Cassidy Bayou, Sumner, Mississippi), is redolent of a spy story. Stoney-faced and with hands in their pockets, they are watching something unpleasant – an execution, maybe? 

In fact, the story lies elsewhere – in the relationship between the two men, who are at a funeral. For decades the black man, Jasper Staples, has been chauffeur and assistant to the white man, Eggleston’s uncle, Adyn Schuyler Senior; in that time he has come to resemble his employer so closely that he unconsciously mimics his facial expression, posture and stance in almost every detail. Unwittingly perhaps, the photograph is a meditation on master/servant relations.

In one sense, Eggleston’s photographs of people are not portraits at all, since he doesn’t even attempt to enter the private worlds of his subjects. I was going to write sitters, but people rarely pose knowingly for his pictures; more often the photographer spots them in the street, the diner, the parking lot or their place of work and catches them in situ – embedded, as it were, in the place where they have their being. 

Collectively, then, his pictures form a portrait not of individuals, but of social relations in America’s deep south – where people seem to know their place, yet at the same time, appear fundamentally alone.

• William Eggleston Portraits at the National Portrait Gallery until 23 October
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