| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-magnification and high-performance zoom lens where the change of irregular illumination in the midst of zooming is small. SOLUTION: This zoom lens is provided with a 1st positive group (Gr1), a 2nd negative group (Gr2), a 3rd negative group (Gr3) and a 4th positive group (Gr4) in order from an object side. Zooming is performed by moving the 2nd group (Gr2) and the 3rd group (Gr3) so that spaces (d4, d6 and d13) between the respective groups are changed. The 1st group (Gr1) and the 4th group (Gr4) are fixed in the midst of zooming, and the zoom lens is provided with a diaphragm (ST) fixed in the midst of zooming on the nearest side to the object.
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