الوصف
A periscope is an optical instrument for observation over, around, or through an object or obstacle that prevents direct line-of-sight. It functions based on the principle of light reflection using a system of mirrors or prisms within a tube.
Features
Light from an object enters the top opening and strikes the first mirror (or prism) at a 45° angle. This light is reflected at a 90° angle down the tube to the second mirror (or prism) at the bottom. The second mirror then reflects the light horizontally into the observer's eye, allowing them to see an image of the object as if they were at the higher vantage point.