Otso Pietinen photographed the Foreign Minister Väinö Tanner (1881–1966) at the Finnish Broadcasting Company on 13 March 1940. Tanner read the terms of the Moscow Peace Treaty that would end the Winter War on the radio at 12 o’clock. In the radio speech that followed, he explained the reasons that led to the peace. Tanner had stayed up the whole night. The harshness and heaviness of the war, the breaking front lines and the terms of peace that followed have been written on his face and eyes.
Otso Pietinen (1916–1993) was the eldest son of the photographer Aarne Pietinen (1884–1946). Aarne Pietinen became a professional photographer at the age of 45 in 1929, when he was hired as a photographer by the newspaper Uusi Suomi. In 1932, Aarne established the photographic studio Aarne Pietinen Oy, which specialised in portrait photography in addition to newspaper and reportage photography, and later also industrial, travel and advertisement photography. The sons of the family, Otso and his younger brother Matti (1919–2009), continued to run the photographic studio Aarne Pietinen after their father’s death. From 1957, the business operated under the name Pietinen Mainosvalokuvaamo, and in the years 1973–1976, it was called Valokuvatalo Otso Pietinen & co.
The photographs of the Pietinen family of photographers have mainly ended up in the appropriate archives to serve as the shared memory of the nation. The collection of early negatives of Aarne Pietinen Oy from the years 1928–1949 is included in the Picture Collections of the Finnish Heritage Agency. The later picture material by the Pietinen family is in the possession of the Finnish Museum of Photography. In addition, prints by the Pietinen family can be found in the collections of almost every museum and archive. At the moment, the Finnish Heritage Agency is digitising the Pietinen collection to increase its recognition and usability. This also ensures the preservation of material with cultural and historical significance. The digitised images are published in the Kuvakokoelmat.fi online service. The pictorial heritage of the Pietinen family of photographers is a nationally significant entity from the perspectives of both history and cultural history. The photographs in the possession of the Finnish Heritage Agency provide a comprehensive view of the events of the emergencies and critical periods in the 1930s–1940s, and they also form a part of the history of photojournalism and photography.