Real image mode finder optical system having an objective lens integrated as a prism with a reflective surface

摘要

A real image mode finder optical system includes an objective lens, an image inverting optical member for erecting an object image formed by the objective lens, and an eyepiece for observing the object image. The objective lens has a reflecting surface and satisfies a condition: 0.1<D/f<0.4 where D is the distance between the exit surface of the objective lens and the entrance surface of the image inverting optical member and f is the focal length of the objective lens. Thus, the real image mode finder optical system are constructed with a small number of parts and compact design.