<P> Perforated gnomons projecting a pinhole image of the sun were described in the Chinese Zhoubi Suanjing writings (1046 BCE--256 BCE with material added until circa 220 CE). The location of the bright circle can be measured to tell the time of day and year . In Arab and European cultures its invention was much later attributed to Egyptian astronomer and mathematician Ibn Yunus around 1000 CE . </P> <P> Some ancient sightings of gods and spirits, especially in temple worship, are thought to possibly have been conjured up by means of camera obscura projections . </P> <P> The earliest known written record of the camera obscura is to be found in Chinese writings called Mozi and dated to the 4th century BCE, traditionally ascribed to and named for Mozi (circa 470 BCE - circa 391 BCE), a Han Chinese philosopher and the founder of Mohist School of Logic . In these writings it is explained how the inverted image in a "collecting - point" or "treasure house" is inverted by an intersecting point (a pinhole) that collected the (rays of) light . Light coming from the foot of an illuminated person would partly be hidden below (strike below the pinhole) and partly form the top part of the image . Rays from the head would partly be hidden above (strike above the pinhole) and partly form the lower part of the image . This is a remarkably early correct description of the camera obscura; there are no other examples known that are dated before the 11th century . </P> <P> The Greek philosopher Aristotle (384 - 322 BCE), or possibly a follower of his ideas, touched upon the subject in the work Problems - Book XV, asking: </P>

Who wrote the earliest surviving description of the camera obscura