The developments claimed by Porta in the second edition of _Natural Magic_ published in 1589 had been described previously by others. Once again he was a copier and popularizer rather than an inventor and discoverer. And that seems proper for a man who was by profession a playwright with a hobby interest in secret things, especially those relating to natural phenomena. During the three decades prior to 1589, important developments were made in the science of optics. Both Barbaro and Benedetti described _camera obscura_ systems fitted with lenses to improve the images, and E. Danti, an editor and translator, explained in 1573 how an upright, instead of an upside down, image could be shown through the use of a lens-mirror system. Monsignor Daniello Barbaro published at Venice, in 1568, _La Pratica della Perspettiva_, “The Practice of Perspective”, a book on optics. He describes the instrument designed by Alberti, the _camera lucida_, and gives an illustration of it. As in the case of Benedetti, Barbaro’s chief title to memory is that he introduced the projection lens to the natural camera, thereby enlarging its scope. Without any lenses even a modern camera would give only inferior results and motion pictures would not be practical. It is also said Barbaro introduced the diaphragm, which is very important as a means of controlling the light in the camera. Giovanni Battista Benedetti, a patrician of Venice, 1530–90, published at Turin a book called _Diversarum Speculationum Mathematicarum et Physicarum Liber_, “A Book of Various Mathematical and Physical Speculations”, in which was included the first complete and clear description of the _camera obscura_ equipped with a lens. The date of the volume was 1585, four years before Porta published his revised edition. Benedetti used a double convex lens. His first knowledge of optics came from a study of Archimedes, whom he admired greatly. But his learning was not confined to optics. He influenced the great Descartes in geostatics, studying the laws of inertia and making the contribution of the path taken by a body going off from a revolving circle, i.e., tangent. In 1553 he reported that bodies in a vacuum fall with the same velocity. Benedetti’s description of the _camera obscura_ included details on how to make the images appear upright. The material is contained in a printed letter to Pierro de Arzonis. First Benedetti discusses light and the fact that a greater light overshadows a smaller, “just as by day the stars cannot be seen.” He then pointed out that if the light were controlled in a camera the outside images could be seen, but if the rays of the sun were allowed to enter (as by making the opening hole too large) then the images would “more or less vanish according to the strength or weakness of the solar rays.” Benedetti continued: