| 摘要 |
PROBLEM TO BE SOLVED: To provide a real-image type variable power finder which has a simple constitution and makes dust inconspicuous although the finder has a power variation ratio exceeding twice. SOLUTION: This finder has an objective system 1 which has positive refracting power, an erected normal image system which makes an intermediate image by the objective system into an erected normal image, and an ocular system 2 which has positive refracting power in order from the object side. The objective system 1 has a 1st group L1 with negative refracting power, a 2nd group L2 with positive refracting power, and a 3rd group L3 with positive refracting power in order from the object side, the erected normal image system consists of a 1st prism L4 and a 2nd prism L5 , and a visual field frame Q is arranged between the 1st prism and 2nd prism. Here, conditions represented as -0.5<n/m<0.5 and 3.5<(m/fe<2> )×1000<11 are met, where (m) is the distance from the visual field frame flank vertex of the 2nd prism L4 to the visual field frame Q, (n) is the distance from the visual field frame flank vertex of the 2nd prisms L5 to the visual field frame Q, and fe is the focal length of the ocular system 2.
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