Harry Callahan is regarded as one of the most influential figures in post-war photography, yet his work is little known in the UK.

Callahan disregarded the limits of conventional landscapes to give equal focus to both broad perspectives and individual details. He described the three themes of his work as 'nature, buildings and people - but his most photographed subject was one person in particular; his wife Eleanor, whom he met in 1933. Due to his crippling shyness, she would be the only woman he would ever photograph for his series of nudes.

Harry Callahan is one of the most important and influential American photographers, whose work spans from the 1940s through to the 1990s. One of Callahan’s main subjects was the city, and whether photographing people on the street or architecture, he was very interested in the things that we see in the world around us. Callahan was really interested in these overlaps between architecture, design and photography, and so in many of his photographs of the street, you will see isolated architectural features. You will also see the legacies of that kind of early, pre-war European photography, where you have a great use of light and dark.

He’s less well known for colour, but in fact made really great work, and very early. Now, when we think about colour photography, we think mostly about somebody like William Eggleston, working in the sixties and seventies; but in fact, Callahan was experimenting with colour as early as 1951. Callahan was shooting with colour transparencies, which offer a really fantastic separation of colour, and great vivid, very, very vivid colours. And at the time they would have just been kept as, almost like colour slides. It wasn’t until the 1980s that he was able, printing at a lab in Germany, to print and dye transfers, which were extremely complex but a very, very sophisticated way of printing colour. And we can see that it’s a dye transfer because both the blue and the red are equally vivid. We would normally expect, with a colour photograph, that if the, sort of, blue and green tones are bright, then the red tones are slightly less bright. So this is a fantastic way of printing colour imagery.

A really key part of Callahan’s practice, which lasted throughout his life, was his interest in abstraction, and we’ll see that in many different ways in this room. Here, for example, he has photographed, quite close-up, a group of ripped posters that are hanging off the wall. This is an interest that he shared with Aaron Siskind, who would work with him at the Chicago Institute of Design; and both Callahan and Siskind were fascinated with the fact that walking around the street, they could find things that resembled, to them, the kinds of abstract paintings that they were seeing in galleries and in exhibitions in America at the time.

Callahan was a very shy person, and although he wanted to make studies of the nude, the only woman that he would photograph would be his wife, Eleanor. They are really unlike almost any other series of nudes made in the twentieth century. These are not about eroticism; they are not about a, sort of, exploitative attitude to the female form; they are an extremely intimate, extremely quiet and very sensitive study of light and shadow, and the kinds of things that the life study was all about.

Pioneering a completely different attitude to the photographing of nature, Callahan was interested not only in obvious natural scenes, but also in fragments of nature. And this is something that we see here in this Weed against the Sky, which has become a very iconic picture in Callahan’s career. In some cases, natural forms become almost sculptural. In other cases, in Weeds in the Snow, which was an early work from 1942, and a very important work for Callahan, we are seeing almost, like, the draughtsmanship of an abstract expressionist drawing. And in some cases, in fact, you can actually imagine Callahan looking at Jackson Pollock and looking at those works where the, sort of, line moves freely over the canvas.

I think this is what makes Callahan really exciting, is that he sees abstraction in the world around him in a very straightforward way. But this isn’t a straightforward picture; in fact, this kind of thing is extremely difficult to print. It’s extremely hard to print a very dark background with very fine white highlights, as Callahan has done here. So we see both his skill as a cameraman, but also his skill in the darkroom, which is something which is always important when thinking about photography.