| 摘要 |
<p>[Problem] To achieve a real-image variable magnification finder that is compact, inexpensive, has a wide angle and a high variable magnification ratio, and that offers satisfactory viewing of a finder image. [Solution] In order from the object side, a real-image variable magnification finder (10) is essentially configured from: an objective lens system (1) comprising a positive first lens (L1), a negative second lens (L2), a positive third lens (L3), and a positive fourth lens (L4); an erecting optical system (2) comprising a plurality of optical members; and a positive eyepiece lens system (3). When varying magnification, the first lens (L1) and the third lens (L3) are fixed in the optical axis direction, and the second lens (L2) and the fourth lens (L4) move in the direction of the optical axis. All of the optical surfaces of the plurality of optical members of the erecting optical system (2) are flat surfaces, and at least one of the plurality of optical members of the erecting optical system (2) is formed from a glass material and satisfies conditional expression (1): 1.6 < Nd, where Nd is the refractive index of the glass material with respect to the d-line.</p> |
