Observation optical system having hand-vibration compensation system

摘要

Disclosed is an observation optical system such as a binocular. A telescopic optical system of the observation optical system is provided with a plurality of optical elements, which are arranged such that the observation optical system has a first optical axis horizontally extending and a second optical axis vertically extending when the binocular is held horizontally by a user. The observation optical system is further provided with first and second compensation optical systems that are movable to shift optical paths of light passed through the first and second compensation optical systems to compensate trembling of image due to hand vibration applied to the observation optical system. The compensation optical systems are constituted and arranged such that movement thereof will not be affected by the gravity.