| 摘要 |
PROBLEM TO BE SOLVED: To obtain a device by which aberration is sufficiently corrected even by attaining miniaturization and a high variable power ratio in a real image type finder provided with the objective lens group of positive power, the condenser lens group of positive power, an erect optical system to erect an inverted image formed by the objective lens group and the condenser lens group and the eyepiece group of positive power through which an erect image is observed. SOLUTION: The condenser lens group is arranged between the image formation surface position of the inverted image and the objective lens group, and also the objective lens group and the condenser lens group satisfy the conditional expression of 1.36<=ϕ/ϕOB<=1.8, then,ϕmeans the synthetic power of the objective lens group and the condenser lens group (power at the time of lowest magnification in the case of the variable power of the objective lens group) andϕOB means the power of only the objective lens group (power at the time of the lowest magnification in the case of the variable power of the objective lens group).
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