Yousuf Karsh, c 1944.

ENGLAND - AUGUST 06: A Kodachrome colour photograph of Armenian-Canadian portrait photographer Yousuf Karsh (1908-2002), by JCA Redhead (1886-1954) during World War Two. His photograph of Winston Churchill [1874-1965], taken in 1941, captured Britain's mood of defiance and brought Karsh international recognition. This photograph is a Kodachrome transparency. Introduced by Kodak in 1935, Kodachrome is regarded as the first 'modern' colour photographic process. Kodachrome film was imported into Britain from the USA and was in very short supply during World War Two. As Head of Kodak Ltd's Photo Finishing department in Harrow, England, Redhead had access to supplies of this scarce colour film. (Photo by SSPL/Getty Images)