View finder optical system

摘要

A view finder optical system comprises an optical path split mirror which divides a second optical axis from a first optical axis of an objective optical system; a predetermined image forming plane arranged on the second optical axis to have an image coming from the objective optical system formed thereon; a first prism arranged along the second optical axis to bring about reflection twice on the second optical axis and to have the incidence plane thereof and a second reflection plane on the same plane; a second prism which is disposed behind the first prism and is provided with a roof type reflection plane for a first reflection and a reflection plane for further reflecting the second optical axis after the second optical axis is reflected by the roof type reflection plane; and an eye-piece on the second optical axis after it comes out from the second prism. The spacing distance between the first optical axis and the optical axis passing through the eye-piece is shorter than a distance between the first optical axis and the predetermined image forming plane. An optical axis which passes through the exit plane of the first prism is arranged to be tilting to an axis which is perpendicular to the exit plane of the first prism.