Aristotle’s observations
Greek philosopher and scientist Aristotle (384-322 B.C.)
comments on pinhole image formation in his work “Problems”.
He asks his readers: "Why is it that an eclipse of the sun, if
one looks at it through a sieve or through leaves, such as a
plane-tree or other broadleaved tree, or if one joins the
fingers of one hand over the fingers of the other, the rays are
crescent-shaped where they reach the earth? Is it for the
same reason as that when light shines through a rectangular
peep-hole, it appears circular in the form of a cone?”
Aristotle found no satisfactory explanations to his observation
and the problem remained unresolved until the 16th century.