Rigmor Dahl was born in Kristiania. She graduated from high school in 1927, before studying at the Norwegian National Academy of Craft and Art Industry and then training as a photographer at Rude Foto.
She worked as a photographer for the ladies’ journal Alle Kvinner from 1939, the year after after it was created by the Gyldendal publishing house, and all the way to 1975. In the press photographers’ club (Pressefotografenes Klubb) she is listed as member no. 1.
Her first years as a press photographer were naturally enough affected by the wartime occupation. She photographed numerous reports that both directly and indirectly had everyday life during the war as their backdrop. Her other pictures reflect the typical content of Alle Kvinner: reports on celebrities, fashion, handicraft, and household issues. These were also the topics that informed her career at the journal until 1975.
She is most famous for her pictures of the liberation in 1945. During the eventful weeks in May and June 1945, she biked around Oslo and used her keen eye for detail to capture people and situations during this moment of euphoria. Some of the pictures were used at the time, but most remained hidden away and forgotten until their publication in Yngvar Ustvedt’s book Frigjøringen i bilder (The liberation in pictures) in 1995.
Rigmor Dahl also frequently worked for Gyldendal’s pictorial magazine Bilder, which came out in 1939–40 and 1945–48. She was also a member of Oslo Kamera Klubb and entered many photography competitions.
In 1945 Rigmor Dahl married Arne Delphin and took his surname. As a photographer, she therefore turns up under both names.