| 摘要 |
PROBLEM TO BE SOLVED: To judge at a glance to what focal distance it is proper to perform variable magnetication by forming an objective lens of plural concave lenses having the different radius of curvature and different distance from an ocular. SOLUTION: The objective lens 11 is integrally formed of three concave lenses 111 to 113. The 1st concave lens 111 is the thinnest in thickness, the 2nd concave lens 112 is second thinnest, and the 3rd concave lens 113 is the thickest. Namely, as for distances between the respective concave lenses and the ocular 12; the distance of the lens 111 from the ocular 12 is the longest and that of the lens 113 therefrom is the shortest. The radius of curvature of the lens surface 11b of the lens 111 is the smallest, and that of the lens surface 11d of the lens 113 is the largest. Therefore, three finders, from a finder for a short focal distance to a finder for a long focal distance, are adjacent, and three optical images having the different magnification can be viewed simultaneously.
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