Zoom lens system

摘要

A zoom lens system includes a first lens group, a second lens group, and a third lens group, in this order from the object. Zooming is performed by moving the first through third lens groups. The zoom lens system satisfies the following conditions: 1 $\begin{array}{cc}0.62<\left(d_{\mathrm{T12}}-d_{\mathrm{W12}}\right)/f_W<1.0& \left(1\right)\\ 4<f_T/f_{12T}<6& \left(2\right)\\ 5<f_T/\&LeftBracketingBar;f_{3G}\&RightBracketingBar;<8& \left(3\right)\end{array}$ wherein dT12 designates the distance between the first and the second lens groups at the long focal length extremity; dW12 designates the distance between the first and the second lens groups at the short focal length extremity; fW designates the focal length of the entire zoom lens system at the short focal length extremity; fT designates the focal length of the entire zoom lens system at the long focal length extremity; f12T designates the combined focal length of the first lens group and the second lens group at the long focal length extremity; and f3G designates the focal length of the negative third lens group.