| 摘要 |
PURPOSE:To obtain a wide angle zoom lens which facilitates adoption of the ont-touch system and has various aberrations corrected well, by satisfying prescribed conditions in a variable power system consisting of two groups, which are arranged in order from the object side and have negative and positive refracting powers respectively, and a lens system consisting of the third group as a relay lens. CONSTITUTION:A zoom lens consists of the variable power system consisting of two groups, which are arranged in order from the object side and have negative and positive refracting powers respectively, and the lens system consisting of the third group as a relay lens system, and the second group is moved on the optical axis to vary variable power, and the first group is interlocked with the second group to keep the focus position constant. In this zoom lens, equations (1) and (2) are satisfied. In equations, beta2t is the lateral magnification of the second group in the longest focal length, and f1 is the focal length of the first group, and (ft) is the longest focal length. Thus, the first group is moved straight to facilitate adoption of the one-touch system, and the wide angle zoom lens which has various aberrations corrected well is obtained. |
