This essay recently published on Isis traces the history of normality’s development through a photographic research program that itself began with a critique of that very concept. In the 1920s, a group of child development researchers around the psychologist and physician Arnold Gesell constructed the photographic dome—at once laboratory, observatory, and film studio—to assess normal mental development. Although seeking to challenge standardized measurements of the normal, the researchers created a set of developmental norms that shaped a universal understanding of what constituted a normal child. This essay examines the foundation of this pervasive knowledge by tracking the material factors of visual technology and media production: organizing scientific research like film production, Gesell and his team began to think of development in photographic sequences. Film technology configured their ideas about the individuality of every child, gave rise to a democratic variety of norms, and linked the scientific laboratory with private households and public life. The essay thus argues that visual technologies, beyond merely providing a scientific method and a means of popular distribution, constituted far-reaching theories regarding the normal child. This media-material perspective demonstrates that focusing on visual technologies in science can help to denaturalize knowledge about human nature.