what it means- Camera obscura is Latin for "dark chamber." It is the name given to a simple device used to produce images that would lead to the invention of photography. Definition-a darkened box with a convex lens or aperture for projecting the image of an external object on to a screen inside, a forerunner of the modern camera. a small round building with a rotating angled mirror at the apex of the roof, projecting an image of the landscape on to a horizontal surface inside. How it works-The Camera Obscura is an ancient optical device. In its most basic form it is, quite simply, a dark room with a small hole in one wall. On the wall opposite the hole, an image is formed of whatever is outside. This image is upside-down (inverted) and back to front (laterally transposed).This happens because light travels in straight lines, a property known as the rectilinear propagation of light.