may pass beside it. If the object be a statue or some living creature, then it must be very much enlightened by casting the sun beams on it by refraction, reflexion, or both." For models that can't be inverted, like living animals or candles, he advised: "let two large glasses of convenient spheres be placed at appropriate distances". The 17th century Dutch Masters, such as Johannes Vermeer, were known for their magnificent attention to detail. It has been widely speculated that they made use of the camera obscura, but the extent of their use by artists at this period remains a matter of fierce contention, recently revived by the Hockney–Falco thesis. German philosopher Johann Sturm published an illustrated article about the construction of a portable camera obscura box with a 45° mirror and an oiled paper screen in the first volume of the proceedings of the Collegium Curiosum, Collegium Experimentale, sive Curiosum (1676). Johann Zahn's Oculus Artificialis Teledioptricus Sive Telescopium, published in 1685, contains many descriptions, diagrams, illustrations and sketches of both the camera obscura and the magic lantern. A hand-held device with a mirror-reflex mechanism was first proposed by Johann Zahn in 1685, a design that would later be used in photographic cameras. The scientist Robert Hooke presented a paper in 1694 to the Royal Society, in which he described a portable camera obscura. It was a cone-shaped box which fit onto the head and shoulders of its user. From the beginning of the 18th century, craftsmen and opticians would make camera obscura devices in the shape of books, which were much appreciated by lovers of optical devices. One chapter in the Conte Algarotti's Saggio sopra Pittura (1764) is dedicated to the use of a camera ottica ("optic chamber") in painting. By the 18th century, following developments by Robert Boyle and Robert Hooke, more easily portable models in boxes became available. These were extensively used by amateur artists while on their travels, but they were also employed by professionals, including Paul Sandby and Joshua Reynolds, whose camera (disguised as a book) is now in the Science Museum in London. Such cameras were later adapted by Joseph Nicephore Niepce, Louis Daguerre and William Fox Talbot for creating the first photographs. Role in the modern age While the technical principles of the camera obscura have been known since antiquity, the broad use of the technical concept in producing images with a