Bert Haanstra began his career as a photographer. First, he joined the Vereenigde Fotobureaux (United Photograph Agencies) and later on he started his own photograph agency under the name of Express.
Around 1941, Bert Haanstra became involved in the resistance movement and supplied the Persoonsbewijzen Centrale with photographs. He more or less took over Carel Blazer’s duties following the latter's arrest in the autumn of 1943. After Germany's capitulation on 7th May 1945, he was an eyewitness to the shoot-out on Dam square. Although the negatives got lost, he carefully kept the prints of the photographs he had taken at the time. During the German Occupation, he had mainly worked for the resistance and the photographs he took were by no means intended for the general pubic.
Bert Haanstra’s name is synonymous with the postwar history of Dutch film in the Netherlands. Already on completion of his evening course at the Rijksakademie (National Academy) in Amsterdam, Haanstra was dreaming of making films. Following the example set by Cees Kerkhof, he hoped to realize his dream by way of photography.