| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an eyepiece lens in which a relatively high magnification for observing a field of view is ensured while a diopter adjustment is enabled and a large pupil diameter is provided, and to provide a finder optical system having the same and an optical apparatus. <P>SOLUTION: The eyepiece lens EL includes, in order from an object side along an optical axis, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having negative refractive power. The eyepiece lens EL is capable of adjusting the diopter by moving the second lens group G2 along the optical axis. The second lens group G2 includes a biconvex lens component L2, and the third lens group G3 includes a meniscus lens component L3 with its convex surface directed toward the object side. The eyepiece lens EL satisfies the following conditional expression: Nn(ABE)>1.870, where Nn(ABE) is an average value of refractive indices for the d-line of the lenses having negative refractive power included in the first lens group G1 and the third lens group G3. <P>COPYRIGHT: (C)2013,JPO&INPIT |
