A camera obscura (pl. camerae obscurae or camera obscuras; from Latin camera obscūra 'dark chamber') is the natural phenomenon in which the rays of light passing through a small hole into a dark space form an image where they strike a surface, resulting in an inverted (upside down) and reversed (left to right) projection of the view outside. Camera obscura can also refer to analogous constructions such as a darkened room, box or tent in which an exterior image is projected inside or onto a translucent screen viewed from outside.
https://en.wikipedia.org/wiki/Camera_obscura