Abstract: An ocular optical system EL for observing an image displayed on an image display element Ob has, in order from the image display element Ob: a first lens L1 which is a positive lens; a second lens L2 which is a negative lens having a strong concave surface facing the image display element Ob; and a third lens L3 which is a positive lens having a strong convex surface facing the eye point EP in order to implement both high magnification and size reduction, wherein the first lens L1 is cemented and integrated with the image display element Ob, in order to reduce the size of the ocular optical system EL while ensuring tele-centricity and sufficiently wide luminous flux.

Abstract: Composing a zoom optical system ZL, in order from an object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having negative refractive power; and disposing each lens group with satisfying a given conditional expression (1); thereby providing a zoom optical system ZL capable of suppressing variation in aberrations upon zooming and carrying out excellent vibration reduction, an optical apparatus equipped therewith, and a method for manufacturing the zoom optical system.

Abstract: An observation optical system for observing an object includes, in order from the object side: a first lens having positive refractive power; a second lens having negative refractive power and a concave surface facing the object side; and a third lens having positive refractive power and a convex surface facing an eyepoint side. An aspherical surface is included on at least one lens surface, and given conditional expressions are satisfied, thereby providing a compact observation optical system having excellent optical performance, a viewfinder equipped with the observation optical system, and a method for manufacturing the observation optical system.

Abstract: Composing a zoom optical system ZL, in order from an object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, a fourth lens group G4 having positive refractive power, and a fifth lens group G5 having negative refractive power; and disposing each lens group with satisfying a given conditional expression (1); thereby providing a zoom optical system ZL capable of suppressing variation in aberrations upon zooming and carrying out excellent vibration reduction, an optical apparatus equipped therewith, and a method for manufacturing the zoom optical system.