Lucien Hervé (1910-2007) is one of the most important artists of architectural photography, best known as the photographer of Le Corbusier, though he travelled all around Europe and the world to work for other architects like Marcel Breuer, Walter Gropius, Oscar Niemeyer, Lucio Costa, Aalvar Alto, Aulis Blomstedt, etc. “The role of the architectural photography is to reveal the work and to remain faithful, with humility, to its creator” (Lucien Hervé) Did Lucien Hervé –working on the commissions– act according to these principles? What did his clients expect him to do? This paper wishes to reveal the details of his commissions (conditions, expectations) using so far unpublished letters from the artist’s archive. Some architects precalculate the ideal weather conditions, others draw sketches to precise the optimal angles or criticise the tone of these photos. Hervé creates big, analytic series on historical and new constructions and creates a dialogue between them. He becomes a self-taught specialist in architecture and urbanism, takes part in CIAM events, organises exhibitions based on the le corbusian theories, composes books and participates in the training of architect students. Architecture was a conviction for him, but it also became a tool in the service of a deeply human message.