Outline
Ibn al-Haytham Shape of the Eclipse
Ibn al-Haytham (965-1041), born in Basra (Iraq) made great progress in understanding the phenomenon of light. With experimental setups he examined the reflection of light in mirrors, not only flat, but also in curved or cone-shaped mirrors.
In his treatise On the Shape of the Eclipse, Ibn al-Haytham investigated the image of a crescent solar eclipse through a pinhole of a camera obscura. Ibn al-Haytham investigated the shape (image) of a crescent solar eclipse through a pinhole of a camera obscura. For a large aperture, the shape looks distorted. To explain this phenomenon, you have to understand that the sun has a width, namely an arc angle of half a degree.
Ibn al-Haytham proposed a point-by-point construction to determine for each and every point which light rays produce the shape. For every point, the amount of light is the addition of all the rays that come together in that single point, and all the points together produce the entire shape.
link: https://www.fransvanschooten.nl/camera.htm
