Beginning in the seventeenth century, the camera obscura became a mechanical instrument that underwent several modifications and improvements, ultimately transforming into a portable device that enjoyed immense popularity until the invention of photography in the early nineteenth century. Throughout the early modern period, the camera obscura was mobilized as a metaphor for vision and the inner workings of the human eye. The act of looking through this device would have had a profound effect on artists and their practice, affording them the opportunity to envision the world in a new and different way, and redefining the relationship between artist and subject. This thesis explores the camera obscura as a historical object and its influence on artistic practice of the seventeenth and eighteenth centuries focusing on the work of Johannes Vermeer (1632-1675), Giovanni Antonio Canal (1697-1768), known as Canaletto, and Thomas and Paul Sandby (1721-1798; 1731-1809).