| 摘要 |
In the device disclosed, eight elements form a Gauss type wide or large aperture objective. The first element counting from the front is a positive meniscus lens of forward convexity, the second is a positive lens of convex curvature toward the front, the third is cemented to the second and is a negative lens of concave curvature toward the rear, the fourth is a negative lens of concave curvature toward the front, the fifth is cemented to the fourth and is a positive lens of convex curvature toward the rear, the sixth is a positive meniscus lens of rearward convexity, the seventh is a bi-convex lens with the rear surface of stronger curvature, and the eighth is a positive lens. The front surface of the second lens is aspherical so that as the distance from the optical axis increases, the deviation of the surface from the spherical surface of paraxial radius increases in a direction toward the front.
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