We touched on a project using a camera obscura in class and I wanted to look into them some more because I find the phenomenon of pinhole images to be pretty interesting. The camera obscura, also known as pinhole camera, is a device that consists of a space enclosed in darkness, except one hole is left open to let light pass through. Photosensitive material is then left on the wall opposite to the hole, and over time the inverted picture of the area outside that is casted on the wall becomes imprinted into the material. While these devices started out quite large, now there are many different kinds of camera obscura that are much smaller in scale. I took a photography course in high school and my teacher made some makeshift camera obscuras using cookie tins, which I thought was really cool. Interestingly enough, camera obscuras were mainly used in the 16th century as a way to view the eclipse without looking directly at the Sun.
If you want to learn more, check out https://www.britannica.com/technology/camera-obscura-photography