Three vignettes demonstrating light projection apparatus. Johann Zahn (March 29, 1641 - June 27, 1707) was a German monk and author of Oculus Artificialis Teledioptricus Sive Telescopium (1685) which contains descriptions, diagrams, illustrations and sketches of both the camera obscura and magic lantern, along with various other lanterns, slides, projection types, peepshow boxes, microscopes, telescopes, reflectors, and lenses. The first camera that was small and portable enough to be practical for photography was envisioned by Zahn in 1685, but it would be almost 150 years before technology caught up to where this was possible to build. In Oculus Artificialis, his comprehensive description of the magic lantern (along with twelve other different lanterns) includes some of these lanterns showing for the first time lens covers. This was an important evolution in the history of the camera, because it meant that the screen could be kept dark while the operator changed the slide. He also illustrated a large workshop camera obscura for solar observations using the telescope and scioptric ball. He also designed several portable camera obscuras, and demonstrated the use of mirrors and lenses to erect the image, enlarge and focus it.