For the twentieth century, it was increasingly clear, was the century of the commom people, and dominated by the arts produced by and for them. And two linked instruments made the world of the common man visible as never before and capable of documentation: reportage and camera. Neither was new [..] but both entered a self-conscious golden age after 1914.[..] "Reportage" - the term first appears in French dictionaries in 1929 and in English ones in 1931 - became an accepted genre of socially-critical literature and visual presentation in the
1920s, largely under the influence of the Russian revolutionary avant-garde who extolled fact against the pop entertainment which the European Left had always condemned as the people's opium. [..] It spread, mainly via the cinema, through the Western avant-garde. [..] In the hands of the avant-garde Left "documentary film" became a self-conscious movement, but in the 1930s even the hard-headed professionals on the news and magazine business claimed a higher intellectual and creative status by upgrading some movie newsreels, usually undemanding space-fillers, into the more grandiose "March of Time" documentaries, and borrowing the technical innovations of the avant-garde photographers as pioneered in the communist AIZ of the 1920s to create a golden age of the picture-magazine: Life in the USA, Picture Post in Britain, Vu in France. [..] The new photo-journalism owed its merits not only to the talented men - even some women - who discovered photography as a medium, to the illusory belief that "the camera cannot lie", i.e. that it somehow represented "real" truth, and to the technical improvements that made unposed pictures easy with the new miniature cameras (the Leica launched in 1924), but perhaps most of all to the universal dominance of the cinema. Men and women learned to see reality through camera lenses.


Eric John Ernest Hobsbawm  from  The Age of Extremes