Patent ID: 8718464

Claim:
A view finder comprising an observation optical system for enlarged observation of information displayed on a display section, wherein the observation optical system comprises: an optical path bending member for bending an optical path; a positive lens group for diopter correction disposed between the display section and the optical path bending member, the positive lens group being moved along an optical axis direction to achieve the diopter correction; and a cemented lens formed by a positive lens and a negative lens cemented together, the cemented lens being not movable during the diopter correction, wherein an angle formed between a principal ray of a maximum angle of view and the display section is in the range of 90±5 degrees, and wherein conditional expression (1) below is satisfied: 1.60 <fc/fL< 2.50 (1), where fc is a focal length of the positive lens group, and fL is a focal length of the observation optical system, and wherein conditional expression (4) below is satisfied: 25<(ν pk−νnk )/( Rck/fL )<40 (4), where νpk and νnk are Abbe numbers with respect to the d-line of the positive lens and the negative lens forming the cemented lens, respectively, Rck is an absolute value of a radius of curvature of a cemented surface of the cemented lens, and fL is a focal length of the observation optical system.