A light reduction device for adjusting an amount of light reaching an imaging device includes: a light shielding plate in which light shielding parts are discretely formed for blocking the light, and a light transmission part is formed for transmitting the light; a first light reduction plate in which light reduction parts are discretely formed for reducing the amount of the light passing through, and a light transmission part is formed for transmitting the light; and a moving unit configured to move at least one of the light shielding plate and the first light reduction plate in a first direction which intersects with an incident direction of the light, in which the light shielding plate and the first light reduction plate overlap each other at least in part, when viewed from the incident direction of the light.