Edward Weston: the greatest American photographer of his generation?

There are 100 vintage prints by Edward Weston currently on show at the City Art Centre in Edinburgh. A smaller show consisting of just 37 prints made by his son from Weston's original negatives opens in London next month. It seems a good time to look again at the work of a great American photographer who revolutionised the form.

Born in 1886 in Chicago, Weston helped to take photography out of the Victorian age, where it had served as a kind of pictorial addendum to painting, and make it modernist in every sense of the word. Whether photographing elemental landscapes, sculptural nudes or everyday objects, Weston's formal brilliance was allied to a democratic approach to his subject matter. He wanted, he said, "to make the commonplace unusual", a statement that has reverberated through photographic practice to the present day.

Looking at his work now, though, it strikes me that what he actually did, more often than not, was make the commonplace wondrous and beautiful. In Weston's still lives, for instance, the tonal quality of his black-and-white prints imbue everyday objects, both natural and man-made, with a heightened presence that sometimes makes them seem almost unreal. In his journals, he wrote that his aim was to render "the very substance and quintessence of the thing itself, whether it be polished steel or palpitating flesh". To this end, he photographed seashells that had been collected by his lover, the photographer and revolutionary Tina Modotti, and transformed them, in her words, into something "mystical and erotic". (A vintage print of one of his seashells, Nautilus, 1927, sold for $1,082,500 at Sotheby's New York in April.)

When he turned his camera on a humble green pepper, he made it look like a modernist sculpture by Hans Arp. In his journal, he wrote, "It is classic, completely satisfying – a pepper – but more than a pepper: abstract, in that it is completely outside subject matter." (I omitted Edward Weston from my recent column on photographers who wrote well; his prose can be ornate and overwritten, but The Daybooks of Edward Weston are nevertheless an illuminating – and, for their time, incredibly honest – insight into the everyday highs and lows of the artistic life.)

The notion of a subject, even one belonging to the natural world like a pepper or a seashell, being "completely outside subject matter" is intriguing. Revealingly, Weston also wrote that something as ordinary and as extraordinary as a pepper "takes one beyond the world we know in the conscious mind". The question is, do Weston's still lives, in all their tonal beauty, their formal perfection, their technical skill, invest these commonplace objects with a heightened presence, or do they capture something innate? For me, his still lives always hover in that strange hinterland between representation and a kind of formal idealising of the subject. Which is perhaps why I find them easier to admire than to love.

Weston was given a Kodak box camera for his 16th birthday by his father. Within a year, he was photographing the parks in his native city on a 5in by 7in camera, and, aged 18, had the resulting work published in a photographic magazine. His only formal training was a short stint at the Illinois School of Photography. Initially, Weston had been a leading exponent of pictorialism – a kind of arty, romanticised style of portraiture that took its cue from the Victorian painters like Whistler.

In 1913, he met the photographer, Margarethe Mather, a self-styled bohemian and the first of a series of flamboyant women drawn to Weston. She nudged him towards a more radical style that came to full fruition when, in 1922, he photographed the Armco Steelworks in Ohio. The results – tall dark towers rising against a stark white sky – were enough to enshrine Weston as an American modernist master.

It was Tina Modotti, another muse who became his lover, who pushed Weston towards an even more radical way of seeing the world though his camera. Having become lovers after she posed for him, they first travelled to Modotti's Mexico in 1923 and remained there for five years. In Mexico, Weston made a series of beautifully intimate nudes of Modotti, but, at her prompting, he also turned his camera on the everyday things around him: household objects as well as the flora and fauna of the country's arid landscape. Weston became absorbed by the camera's ability to capture, in arresting close-up, the otherness of the country's plant and vegetable life as well as rock and cloud formations. An aesthetic was born.

On his return to California, he continued to use his camera as a means to express "the very substance and the quintessence of the thing itself", photographing in close-up what he saw around him: an egg-slicer, a toadstool, a cup, a gnarled tree. In 1930, another lover, Sonya Noskowiak, brought him some green peppers to photograph, the most famous of which, Pepper No. 30, he transformed into a sensual object with curves that echo both modernist sculpture and the human form. Here, ultra-realism shades into surrealism.

In 1932, alongside Ansell Adams and Imogen Cunningham, Weston joined Group f/64, a collective of west coast photographers named after the smallest aperture in the large-format cameras that they used. Their aim was to champion what soon came to be known as "straight photography", which, in their manifesto, they defined as "possessing no qualities of technique, composition or idea, derivative of any other form".

Weston still considered himself a realist, but, as his work shows, his restless imagination could not be contained by labels or movements. His work throughout the 1920s can be read as a record of how photography moved from the pictorial to the modernist and beyond, becoming in the process an art form in and of itself.

For all that, the work he made towards the end of his life has always intrigued me more than his still lives or nudes. From 1938 until his death in 1958, Weston lived in a wooden cabin on Wildcat Hill in Carmel, California, near Point Lobos, a huge stretch of shoreline that he photographed again and again. A rocky outcrop on the edge of the continent, now called the Point Lobos state reserve, it is a beautifully elemental place that remains much as it was in Weston's time. It is a wild place that drew artists, photographers and film-makers long before Weston settled there.

For me, Weston's black and white images of Point Lobos – its angular rocks, tangled seaweed, bent cypress trees, sun-scorched driftwood – possess an almost unearthly beauty that is both austere and sensual, somehow not so "heightened" through technique as his more famous pictures. These images possess presence, but you feel it is captured, not created, by the camera.

Weston's final photographs, made in the years before he was diagnosed with Parkinson's disease in 1946, give off such a profound sense of place that Point Lobos now belongs to Edward Weston in much the same way that the Yosemite national park belongs to Ansel Adams. One of the last photographs he made is called The Dody Rocks, Point Lobos. It is subtitled Something Out of Nothing, a title that says much about how his ever-restless imagination had found yet another way of seeing, and one that perhaps surprised even himself in its rendering of "the very substance and quintessence" of that extraordinary landscape.

The exhibition takes place at Chris Beetles gallery, 8-25 September 2010. Phone: 020 7839 7551