French military cinematographer, circa 1917. From the National Archives, The Hague (Holland)
An interesting example how films were used by the U.S. Army for military training comes from U.S. Signal Corps footage that was uploaded by the National Archives in January 2015 on the Internet. The footage was edited into the "Historical Series" which was compliled by the U.S. Signal Corps in 1936.
New Camera TechniquesThis World War I film shows in detail the nomenclature, assembly and disassembly, and operation of a Lewis machine gun. Reel 2 shows infantry troops at Camp Meade, Maryland, lined up in various battle formations. The first reel is particularly interesting because it shows how the U.S. Signal Corps used new camera techniques such as 'stop motion capture' to demonstrate the use of the Lewis machine gun.
The military training film by the U.S. Signal Corps can be watched here.