Briefing images issued by INS Department of Propaganda, November 2004

The making of aerial photos: Single lens aerial camera: left equipped with view finder for oblique photography; right mounted for vertical photography and equipped for automatic operation, intervalometer at right, view finder in foreground; single lens vertical photo showing badlands type of erosion in loess, silt and shale. (H. T. U. Smith, Aerial Photographs and their Applications, London: D. Appleton-Century, 1943, pl. 2)