British director and screen writer, she is not to be confused with the American actress of the same name. Mary Field is best known for directing short educational and nature films.

Field became the series director of Secrets of Nature in 1929. Previously a history teacher, she joined the film industry as an historical consultant in 1925, working for British Instructional Films. Although she had no training in science or filmmaking, Field quickly proved herself to be a first-class film director, developing a unique style that fused education and instruction.

Field insisted that nature films were more than just a series of impressive images: they were the result of a painstaking process that involved scriptwriting, editing, filming, cutting and montage and synchronisation, as well as the collaboration of expert consultants.

She continued to direct nature films under the new title Secrets of Life from 1934 when her production team, led by H. Bruce Woolfe, moved from British Instructional Films to Gaumont-British instructional. During the Second World War, she put her skills to work in producing public information films for the British government and was later commissioned to produce a series of educational films for the British Council. Field was a pioneer in understanding how children related to the cinema, and spearheaded attempts to adapt films to their taste. Her 1954 Carnegie report, Children and Films: A Study of Boys and Girls in the Cinema, investigated the reactions of children to a series of films by means of infra-red photography. Previous reports into children’s reactions to cinema had been based on questionnaires. Field had been interested in audience’s reactions long before this – as early as the late 1920s, she was adapting many of the Secrets of Nature films based on audience feedback.