A Dufaycolor colour transparency of a broad avenue in Helsinki, Finland, taken by an unknown photographer in about 1938. People wait for a tram at the Asema Station stop. The Dufaycolor process was introduced as cine film in 1932 and as rollfilm for still photography in 1935. Based on Frenchman Louis Dufay's (1874-1936) Dioptichrome process of 1908, it was the last 'additive' colour process to be marketed. Dufayclor consisted of a very fine, filter regular screen made up of red, green and blue lines printed on a film base. The process was popular with both amateur and professional photographers and survived until the 1950s.
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