Photography is the result of combining several different technical discoveries. Long before the first photographs were made, Chinese philosopher Mo Ti and Greek mathematicians Aristotle and Euclid described a pinhole camera in the 5th and 4th centuries BC. In the 6th century CE, Byzantine mathematician Anthemius of Tralles used a type of camera obscura in his experiments Ibn al-Haytham (Alhazen) (965–1040) studied the camera obscura and pinhole camera, Albertus Magnus (1193/1206-1280) discovered silver nitrate, and Georges Fabricius (1516–1571) discovered silver chloride. Daniel Barbaro described a diaphragm in 1568. Wilhelm Homberg described how light darkened some chemicals (photochemical effect) in 1694. The novel Giphantie (by the French Tiphaigne de la Roche, 1729–1774) described what can be interpreted as photography. The early cave paintings attest to the fact that man has always wanted to record himself, his activities and the environment around him. This art, until very recently, has been reserved for the talented individuals, not the everyday, ordinary person. Painters of great renown abound throughout the centuries and have left remarkable pictorial histories of our journey through time. While the camera was not invented until the 19th century, the two basic elements of a camera had been well known for hundreds of years. The first element of a working camera known by the ancients is the effect of a lighted area separated from a dark area with only a pin hole opening between them. An inverted (upside down) image of the lighted area will be produced on a flat surface in the dark area. As early as the 1400's it was documented that inserting a lens in the hole would produce a crisper, clearer image. This technology, called "camera obscura" was often used by artists to sketch objects more quickly and ease the difficulties of depth perception. The image was allowed to be projected on a piece of paper inside a dark box and the artist would trace outlines of the projected image. The second known element of a working camera was the existence of materials capable of permanent change when exposed to light. These light sensitive chemicals were experimented with for centuries but were not used to coat a flat surface until very recently. Putting these two pieces of knowledge together proved difficult. Early in the 1800's, the first experiments took place attempting to make images on paper surfaces that had been coated with light sensitive material. The process worked, but a lot of logistical problems needed to be solved. The first major problem was making the captured image on the chemical coated surface permanent. This problem was finally solved with the Daguerrotype image and made a huge impact on the world when it was announced in 1839. However other difficulties remained to be solved.