 Complete the following phrase:  The early commercial success and spread of photography can be attributed to the recognition of photographys potential to spread information on Cochin China, Tonkin, and Annam by colonial administrators. Thus photographers were often tasked to record early military expeditions. For instance, Émile Gsell 1838  1879 was hired to photograph Angkor Wat in the Commission dexploration du Mékong. Gsell would later be the first Frenchman to set-up a commercial photography studio in Saigon. Other notable French photography studio owners include Aurélien Pestel 18551897 whose photographs were exhibited at the 1894 World Exposition in Lyon and used to announce Indochinas participation in the 