Light consists of an endless number of light dots, reflected by objects or people, spreading linear or in waves, leading to this phenomenon in the dark. The dark room is camera obscura, in which light falls through a small hole to project an image upside down, inverted and in natural colors.
Astronomers got interested in the camera obscura. They found that by using the camera obscura, they could view solar eclipses without staring directly at the sun and damaging their eyes. A simple pinhole camera is still used today as a means to view solar eclipses. The camera obscura was also used in the 16th century to observe the heavens (Naughton, 2003; Bradley, 1991). The use of the camera obscura in science, art and entertainment which was somewhat limited because lasting images would not be recorded other than by tracing the image produced.
Iraqi scientist Alhazen invented camera obscura, which is also described in his Book of Optics (1011-1021). English scientists Robert Boyle and Robert Hooke later invented a portable camera obscura in 1665-1666. In the 1500s many artists, including Michelangelo and Leonardo da Vinci, used the camera obscura to help them draw pictures.