Weston studied medicine at the insistence of his parents; but, after receiving his medical diploma in 1870, he went to New York City, where he was employed as a chemist. While working with an electroplating company, he decided that a generator would be more efficient than batteries as a source of power for electroplating. He subsequently invented and manufactured a highly successful electroplating dynamo.

Overshadowed by others in the field of lighting (arc and incandescent), Weston in 1886 turned his attention to the design and manufacture of electrical measuring instruments. In 1888 he organized the Weston Electrical Instrument Company, which became world famous for its high-quality electrical products. Weston became a U.S. citizen in 1923.

Weston was born into a family of some intellectual substance—his father was a medical doctor and his grandfather a professor of literature—but, as a young man, he found little redeeming virtue in books and did not finish high school. The learning that he finally achieved, while not negligible, was of that spotty and eccentric character that generally identifies the autodidact. At 16 he received his first camera as a gift from his father, and from that time everything that he read and all that he experienced, both artistically and personally, was processed as food for a fierce artistic ambition. After studying for a time at the Illinois College of Photography, in 1911 he moved to California, where he would spend most of his life.

In some ways, Weston would seem an unlikely candidate for the role of hero to modern American photography. By his mid-30s he was a skilled but unexceptional portrait photographer working in the Los Angeles suburb of Glendale. He was also an active and very successful participant in the contests of the conservative photographic salons, a network of self-sanctioning clubs that awarded ribbons and medals. His work through the early 1920s was a better-constructed version of the standard fare of these salons—work in the Pictorialist style, in which photographers imitated paintings by suppressing detail, manipulating images in a darkroom, and depicting traditional painting subjects such as pastoral landscapes, romantic marine scenes, children and pets, still lifes, and nudes. Members of these salons tended to associate artistic virtue with a kind of abstractness that eliminated subjects of pointed specificity: the subject was seldom identifiable as a particular landscape, sailboat, or undressed woman, and it was rarely identifiably contemporary.

Beginning in the early 1920s, Weston became impatient with his easy victories in this milieu, and he began to work his way toward a specifically photographic aesthetic (i.e., one that addressed the particular qualities of photography, rather than the qualities of painting) and, more slowly, toward a broader and more vernacular definition of artistic subject matter. When he first began to challenge the standards of the salons, it was more in manner than content: his first, tentatively rebellious pictures of the early 1920s exhibit a new forcefulness of design and an appreciation of the flat picture plane, but they do not challenge the basic Pictorialist conception of appropriate content.

Until well into his 30s, Weston was geographically and intellectually isolated from the main currents of advanced American photography, and of modern art in general. Alfred Stieglitz (Stieglitz, Alfred), Edward Steichen (Steichen, Edward), Paul Strand (Strand, Paul), Charles Sheeler (Sheeler, Charles), and Ralph Steiner all worked in the East. In California, Ansel Adams (Adams, Ansel) had not yet begun his important work, and Imogen Cunningham (Cunningham, Imogen) was a long day's journey north in San Francisco. While later photographers became widely known more through books and magazines than by virtue of their original prints, in the mid-1920s the best photomechanical reproduction was both rare and generally unsatisfactory, and so the work of other photographers was not readily available to Weston. It is startling to recall that no illustrated monograph existed on any of the aforementioned figures until 1929, when Carl Sandburg (Sandburg, Carl) wrote Steichen the Photographer—about his brother-in-law.

Thus, to a remarkable degree, Weston invented a powerful version of modern photography out of his own imagination and prodigious will. He was voraciously curious and was influenced by the ideas and passions of other artists as much as by their work. In 1922, during a visit to New York, he met Stieglitz, and he later remembered the meeting as challenging and enlivening. The next year he went to Mexico with his student and mistress, Tina Modotti, and there met Diego Rivera (Rivera, Diego), José Clemente Orozco (Orozco, José Clemente), David Alfaro Siqueiros (Siqueiros, David Alfaro), and other figures of the Mexican artistic renaissance, who received and criticized him as a fellow artist.

While in Mexico, Weston produced what are his first radically independent pictures, notably a series of heroic, frame-filling heads (e.g., Nahui Olin, Guadalupe Marin de Rivera, and Manuel Hernandez Galvan, all 1924), and similarly minimal works such as Palma Cuernavaca and Excusado, both from 1925.

It was during this period (c. 1930–33) that Weston developed his mature technique, abandoning soft-textured papers and slow, luxurious tonal gradations for a vocabulary that was fundamentally that of the industrial photographer: all-over sharpness, a full tonal scale, and smooth surface papers that would record the maximum of both tone and texture. For some portraits and nudes he used a Graflex camera, which could be held in his hands and which allowed quick response to a subject in flux, but for most of his work he used an 8 × 10-inch view camera and printed its negatives by contact.

In 1932 Weston became a founding member of Group f.64, a loose and short-lived collection of purist photographers that included Adams and Cunningham. Since 1917 he had kept a “daybook,” in which he confided his professional triumphs, his economic crises, his relationship to friends and family, his impressively demanding love life, and—most especially—the progress of his artistic life. For the critic and the student, it is important to note that in 1934 he stopped making regular entries in his diary, presumably outgrowing the need for it once he was ready to begin his greatest work.

From 1934 through 1948, his last working year, Weston continued to explore his favourite subject matter: natural forms, landscape, nudes, and people. His development was guided by a cool analytical intelligence that allowed him to proceed quite consciously from simpler to increasingly complex problems. The nature of this artistic evolution can perhaps be seen most clearly in the genre of landscape. In 1922 Weston wrote that his style of “straight” photography could not deal successfully with landscape, “for the obvious reason that nature unadulterated and unimproved by man—is simply chaos.” However, by the spring of 1929 he began to photograph Point Lobos, perhaps the longest-lasting and most fecund of all his subjects. At first he “did not attempt … any general vista,” but rather focused only on details of the roots and trunks of cypresses. Again expanding his views, however, two years later in his “daybook” he ruminated over “an open landscape, or rather a viewpoint which combines my close-up period with distance; a way I have been seeing lately.” By the mid-1930s his landscapes often included a horizon, and they described deep space in a naturalistic way, without sacrificing the formal rigour that he had achieved earlier within a shallow pictorial space.

The evolution of his nudes followed a comparable pattern of evolution: by the mid-1930s they began to represent not an abstract woman, but specific people, often with their faces visible, who exist in a particular environment at a particular moment. Similarly, the greatest of his portraits are those that he did of his own family in the mid-1940s as he unknowingly approached the end of his productive life. These portraits are so generous in their acceptance of the contingent world that they might be viewed as the apotheosis of the family snapshot, but in the clarity of their vision and the suppleness of their technique they are unforgettable.

In 1937 Weston received the first Guggenheim Fellowship given to a photographer. The fellowship was renewed for the following year, and the project resulted in the book California and the West (1940), which included an excellent text by Weston's second wife, Charis Wilson. Other notable books on Weston's work were published in the 1940s, including Fifty Photographs: Edward Weston (1947), the result of Weston's own very interesting selection of his work, and the slim but very influential Edward Weston (1946, edited by Nancy Newhall), which accompanied his major one-man exhibition at the Museum of Modern Art in New York City. Neither Weston nor his friends realized that a slight uncertainty of movement evident at the time of the show was a symptom of Parkinson's disease. The disease quickly limited his mobility, and he made his last photograph, on Point Lobos, in 1948, a decade before his death.

During the period between the two world wars, the vital tradition of American photography might be imagined as an axis, with the work of Walker Evans at one end and that of Edward Weston at the other. Whereas Evans seemed to make his art out of plain facts, selected by a superior intelligence and arranged in the most stringent order, Weston made his out of tactile surfaces and organic forms, and, most of all, out of the pleasure of sight itself. Among Weston's most conspicuous heirs one might count Minor White (White, Minor), Aaron Siskind (Siskind, Aaron), Jan Groover, and Ray Metzker.