| 摘要 |
A wide-angle zoom lens system including a negative first lens group, a positive second lens group, a diaphragm, and a positive third lens group, in this order from the object; whereby upon zooming from the short focal length extremity towards the long focal length extremity, each lens group is arranged to move so that the space between the first and second lens groups and the space between the second and third lens groups are narrowed; and the diaphragm moves integrally with the third lens group. At least one negative lens element having a concave surface facing towards the image is provided in the first lens group, and the concave surface of the at least one negative lens element is an aspherical surface; and the wide-angle zoom lens system preferably satisfies the following condition;whereinX1 designates the distance, along the optical axis, between the aspherical surface in the first lens group and the diaphragm at the long focal length extremity; andfS designates the focal length of the entire lens system at the short focal length extremity.
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