Judy Dater is an American photographer and feminist. She is perhaps best known for her 1974 photograph, Imogen and Twinka at Yosemite, featuring an elderly Imogen Cunningham, one of America's first woman photographers, encountering a nymph in the woods of Yosemite. The nymph is the model Twinka Thiebaud. The photo was published in Life magazine in its 1976 issue about the first 200 years of American women. Her photographs, such as her Self-Portraiture sequence, were also exhibited in the Getty Museum. Dater was born in 1941 in Hollywood and grew up in Los Angeles. Her father owned a movie theater, so movies became the prism through which she viewed the world and they had a profound influence on her photography. She studied art at UCLA from 1959 to 1962 before moving to San Francisco and received a bachelor's degree in 1963 and a master's degree in 1966, both from San Francisco State University. It was there she first studied photography with Jack Welpott, whom she later married. In 1975, they published a joint work, titled Women and Other Visions. They were divorced in 1977. In 1964, Dater met the photographer Imogen Cunningham at a workshop focusing on the life and work of Edward Weston at Big Sur Hot Springs, which later became Esalen Institute. Dater was greatly inspired by Cunningham's life and work. They 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. Dater became part of the community of the west coast school of photography, primarily represented by the photographers Ansel Adams, Brett Weston, Wynn Bullock and Cunningham. They all took an interest in her work and encouraged her to pursue photography as a career.