became a standard feature on smartphones, taking pictures (and instantly publishing them online) has become a ubiquitous everyday practice around the world. Etymology The coining of the word "photography" is usually attributed to Sir John Herschel in 1839. It is based on the Greek φῶς (phōs; genitive phōtos), meaning "light", and γραφή (graphê), meaning "drawing, writing", together meaning "drawing of light". Early history of the camera A natural phenomenon, known as camera obscura or pinhole image, can project a (reversed) image through a small opening onto an opposite surface. This principle may have been known and used in prehistoric times. The earliest known written record of the camera obscura is to be found in Chinese writings by Mozi, dated to the 4th century BCE. Until the 16th century the camera obscura was mainly used to study optics and astronomy, especially to safely watch solar eclipses without damaging the eyes. In the later half of the 16th century some technical improvements were developed: a biconvex lens in the opening (first described by Gerolamo Cardano in 1550) and a diaphragm restricting the aperture (Daniel Barbaro in 1568) gave a brighter and sharper image. In 1558 Giambattista della Porta advised using the camera obscura as a drawing aid in his popular and influential books. Della Porta's advice was widely adopted by artists and since the 17th century portable versions of the camera obscura were commonly used — first as a tent, later as boxes. The box type camera obscura was the basis for the earliest photographic cameras when photography was developed in the early 19th century. Before 1700: Light sensitive materials The notion that light can affect various substances — for instance, the sun tanning of skin or fading of textile — must have been around since very early times. Ideas of fixing the images seen in mirrors or other ways of creating images automatically may also have been in people's minds long before anything like photography was developed. However, there seem to be no historical records of any ideas even remotely resembling photography before 1700, despite early knowledge of light-sensitive materials and the camera obscura. In 1614 Angelo Sala noted that sunlight will turn powdered silver nitrate black, and that paper wrapped around silver nitrate for a year will turn black. Wilhelm Homberg described how light darkened some chemicals in 1694. 1700 to 1802: earliest concepts and fleeting photogram results Schulze's Scotophors: