in 1906 she was studying at the University of Washington in Seattle, where she was inspired to take up photography by an encounter with the work of Gertrude Käsebier.With the help of her chemistry professor, Horace Byers, she began to study the chemistry behind photography and she subsidized her tuition by photographing plants for the botany department.
In 1907, Cunningham graduated from University of Washington with a degree in chemistry. Her thesis was titled “Modern Processes of Photography.”
After graduating from college in 1907, Cunningham went to work for Edward S. Curtis in his Seattle studio, gaining knowledge about the portrait business and practical photography. They were documenting American Indian tribes together for the book The North American Indian, which was published in twenty volumes between 1907 and 1930.
in 1909 Cunningham traveled to Germany to study with Professor Robert Luther at the Technische Hochschule in Dresden, Germany. In Dresden she concentrated on her studies and didn't take many photographs. In May 1910, she finished her paper, "About the Direct Development of Platinum Paper for Brown Tones", describing her process to increase printing speed, improve clarity of highlights tones, and produce sepia tones.
In Seattle, Cunningham opened a studio and won acclaim for portraiture and pictorial work. Most of her studio work of this time consisted of sitters in their own homes, in her living room, or in the woods surrounding Cunningham's cottage. She became a sought after photographer and exhibited at the Brooklyn Institute of Arts and Sciences in 1913.
In 1914, Cunningham's portraits were shown at An International Exhibition of Pictorial Photography in New York. Between 1915 and 1920, Cunningham continued her work and had three children with Roi Partridge.
In 1920, the family moved to San Francisco where Partridge taught at Mills College. Cunningham refined her style, taking a greater interest in pattern and detail and becoming increasingly interested in botanical photography, especially flowers. Between 1923 and 1925 she carried out an in-depth study of the Magnolia flower. Later in the decade she turned her attention toward industry, creating several series of industrial landscapes in Los Angeles and Oakland.
in 1930 she joined for group f64. f/64 group includes: Ansel Adams, John Paul Edwards, Preston Holder, Consuelo Kanaga, Alma Lavenson, Sonya Noskowiak, Henry Swift, Willard Van Dyke, Brett Weston, Edward Weston, and of course Imogen Cunningham. This group was using their photography in a new way, representing something that steered away from the pictorialism norm.
In the 1940s, Cunningham turned to documentary street photography, which she executed as a side project while supporting herself with her commercial and studio photography. In 1945, Cunningham was invited by Ansel Adams to accept a position as a faculty member for the art photography department at the California School of Fine Arts.
In 1964, Imogen Cunningham met the photographer Judy Dater while leading a workshop focusing on the life and work of Edward Weston in Big Sur Hot Springs, California which later became the Esalen Institute. Dater was greatly inspired by Cunningham's life and work. Cunningham is featured in one of Dater’s most popular photographs Imogen and Twinka at Yosemite, which depicts elderly Cunningham encountering nude model Twinka Thiebaud behind a tree in Yosemite National Park.
The two shared an interest in portraiture and remained friends until Cunningham's death in 1976. Three years later, Dater published Imogen Cunningham: A Portrait, containing interviews with many of Cunningham's photographic contemporaries, friends, and family along with photographs by both Dater and Cunningham.