In 1970 American fashion and portrait photographer Irving Penn published a book of photographs, Worlds in a Small Room. It was the culmination of an occasional project that had absorbed him for more than 20 years, spanning Africa, the Middle East, Europe, North and South America.

Penn sought to photograph indigenous people in the style of 19th-century portrait photographers, using natural northern light in studios.

As we might expect from the world’s leading fashion photographer, Penn’s images were beguiling and seductive. To contemporary eyes, they have something of a benign visual colonialism about them, occupying a gap between Vogue and National Geographic. Some sitters came as they were, others were encouraged to wear tribal or ceremonial costumes in much the same way as the photographer Edward Curtis, in the early 1900s, dressed native Americans from props bought from a Wild West show. Inevitably, we perceive these portraits through the eyes of a stranger. They are idealised constructs of our Western notion of the exoticness of other people.

“You Look Beautiful Like That, the Portrait Photographs of Seydou Keita and Malick Sidibe” on display at the National Portrait Gallery, London, is very different. These are pictures taken inside the culture they portray, the work of two commercial photographers who ran studios in Bamoka, the capital of Mali in west Africa. Both Keita and Sidibe worked in the decades before and after Mali’s independence from France in 1960. Their portraits map the shifting tensions between African and Western values and chart an important chapter in Mali’s history. In an interview with the exhibition curator Michelle Lamuniere, Malike Sidibe recalled that: “There was another kind of independence too. By 1956 Afro-Cuban music had hit Africa along with European music, and this allowed young people to experience a different kind of freedom.”

The photographs positively crackle with this new-found sense of freedom as the sitters try on different forms of cultural identity and experiment with clothing, hairstyles and the accoutrements of urban sophistication such as watches, radios, motorbikes and sewing machines. But these are more than dry social documents; they are rooted in the commercial transaction of visiting the high-street photographer and paying to have your portrait made.

Once commissioned, the images were intended to be seen and shared by friends and relatives. Printed as postcard-sized contact pictures they were often mailed from the cities back home to rural communities as evidence of a new-found urban sophistication. Faced by a photographer who was both director and audience, asked to pose among the printed fabric backdrops and to select a range of props that variously symbolised tradition and modernity there was little doubting the role expected of these young Malians as they entered the studio. They were there to perform and Keita and Sidibe encouraged informal poses and individual expression. “You Look Beautiful Like That” is a translation of “i ka ny tan”, the phrase used by the photographers to reassure their clients. There is something in the pictures of the dance hall and the theatre: they are at once removed from the photographer Henri Cartier Bresson’s claim that having your portrait made lies somewhere between visiting the dentist and the psychiatrist. In the early days, Keita recalled: “To have your photo taken was an important event. The person had to be made to look serious, and I think they were intimidated by the camera.” That sense of creeping uncertainty produced an inevitable tension discernible in some of the portraits.

Keita died in 2001 aged 80, while Sidibe is still active. He has turned his attention to meeting the interests of Western curators, publishers and dealers. In the 1990s, their work became increasingly well known through a series of exhibitions in New York and Paris. What had been private pictures made for paying clients suddenly became public images feted by the art world and pursued by dealers interested in acquiring tranches of negatives and to publish the work for the growing collectors’ market. While Sidibe recalls a portrait would have cost “around the price of a meal out in Bamoko”, a Keita print recently sold for $12,000 at an auction in New York, about the cost of a down-payment on the restaurant. The two photographers were delighted, with Keita telling Lamuniere: “You can’t imagine what it was like for me the first time I saw prints of my negatives printed large scale, no spots, clean and perfect. I knew that my work was really, really good. The people in my photos looked so alive, almost as if they were standing right in front of me, in the flesh.”

The two photographers became friends, having maintained a polite professional distance during the era of their greatest activity. “Here in Africa, there is a strong distrust of competition. If I started showing up at his studio and then later on his business started to flounder, he might well think, ‘That young guy put a spell on me!’ ” recalled Sidibe. In an ironic connection back to Irving Penn, both were invited to make fashion photographs for French and American magazines in which they recreated their earlier portrait style. However their greatest legacy will be their pictures of the people of Bamoko, a city many of us might struggle to pinpoint on the map. In an age when the image of western Africa is dominated by conflict and dependence, these portraits reveal a rare glimpse into people’s hopes and dreams and sheer sense of being.

“You Look Beautiful Like That, the Portrait Photographs of Seydou Keita and Malick Sidibe” at the National Portrait Gallery, London, until June 8, admission free Tel: 020 7312 2452 Roger Hargreaves is education officer at the National Portrait Gallery

Lesson ideas

Key stage 1

Explore identity. Discuss hairstyles and colours. Make template faces on a photocopier and use fabrics and materials to make a variety of stuck-on styles.

KS2

Seydou Keita and Malick Sidibe made great use of patterned fabrics in the floor and walls of their studies. Make collaged pictures incorporating a range of materials to which can be added cut-out figures. The pictures can be re-photographed on a digital camera and a gallery set up on the computer.

KS4

Discuss high street portrait photographers from around the world. What do their pictures reveal about the communities they represent?

Websites

National Portrait Gallery www.npg.org.ukliveylblt.asp

Mike Disfarmer captured the honesty and determination of the people of Heber Springs, Arkansas, US, during the 1930s www.disfarmer.com

The Photographers’ Gallery, London, had an exhibition last year of Harry Jacobs’ studio portraits in Brixton covering the 1950s to the 1990s.

www.photonet.org.ukprogrammepastbrixtonbrixton.html

August Sander photographed the people of Cologne at the time of the collapse of Weimar Germany and the rise of Nazism www.masters-of-photography.comSsandersander.html

The work of early 1900s North American photographer Edward Curtis can be viewed at www.escurtis.com