| 摘要 |
These variable-magnification observation optics are provided with an objective system, an erecting system, and an eyepiece system. In order from the object side, the objective system comprises a positive first group, a positive second group, and a negative third group. In order from the object side, the eyepiece system comprises a positive fourth group and a positive fifth group. The erecting system is located between the first and second groups. In order from the object side, the fifth group comprises a negative meniscus lens, the concave surface of which faces the object side, and a positive lens, with an air gap therebetween. The fifth group has at least one aspheric surface. |
