Devices that project images can be used for copying and enlarging. The earliest known instrument like this is the camera obscura or pin-hole camera, crude forms of which have been around since the fifth century. The camera obscura, predecessor to the photographic camera, is a box with a hole in one side, through which an inverted image of an outside scene is naturally projected onto the opposite side, or in the case of a dark room or tent onto the opposite wall. They were refined during the 1600s to include a converging lens. The camera lucida was patented in 1806 by William Wollaston for drawing copies or reductions from an original. A prism reflects the image of a distant scene or subject onto a sheet of paper below the prism over which the user can place a transparency and copy the image. The camera lucida was popular with artists throughout the nineteenth century and lived on throughout the twentieth century in some drawing, drafting and photogrammetric labs.