Periscope

British soldier in World War I using a periscope to see from a trench

Design of a persicope. The model on the left uses mirrors, the one on the right uses prisms

A periscope is an optical instrument that is used to watch a scene from cover. The classical design uses a number of mirrors or prisms, and is used in tanks and submarines.

Periscope Media

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  Principle of the lens periscope.*The two periscopes differ in the way they erect the image. The left one uses an erecting prism whereas the right uses an erecting lens and a second image plane.*a Objective lens*b Field lens*c Image erecting lens*d Ocular lens*e Lens of the observer's eye*f Right-angled prism*g Image-erecting prism

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  1889 Arthur Krebs & Jean Rey periscope for the French submarine Gymnote