Sex cam arba
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.
Lit objects reflect rays of light in all directions.
A small enough opening in a screen only lets through rays that travel directly from different points in the scene on the other side and these rays form an image of that scene when they are collected on a surface opposite the opening.
from Latin, meaning "dark room": camera "(vaulted) chamber or room," and obscura "darkened, dark"), also referred to as pinhole image, is the natural optical phenomenon that occurs when an image of a scene at the other side of a screen (or for instance a wall) is projected through a small hole in that screen as a reversed and inverted image (left to right and upside down) on a surface opposite to the opening.
Although the image is viewed from the back, it is now reversed by the mirror.
A camera obscura device without a lens but with a very small hole is sometimes referred to as a "pinhole camera", although this more often refers to simple (home-made) lens-less cameras in which photographic film or photographic paper is used.
Rays of light travel in straight lines and change when they are reflected and partly absorbed by an object, retaining information about the color and brightness of the surface of that object.
Using mirrors it is possible to project a right-side-up image.
The projection can also be diverted onto a horizontal surface (e.g. The 18th-century overhead version in tents used mirrors inside a kind of periscope on the top of the tent .