| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zoom lens capable of easily obtaining high optical performance in a basic state and an extender switch state by appropriately setting a relay section and lens configuration of an extender while restricting an increase in the full length of the relay section. <P>SOLUTION: A zoom lens comprises, in order from object- to image-side: a focus lens section U1; a zoom section LZ including a lens group for zooming; an aperture stop SP; and a relay section U4 immobile upon zooming. The relay section includes a 41st group, and 42nd and 43rd groups detachable from an optical path. In order to change a focus distance range of the entire system, the relay section has a 44th group that is inserted into an optical path accompanying the retreating of the 42nd group from the optical path. In a state where the 44th group is inserted into the optical path, a distance l_out from the aperture stop to the final lens face of the 44th group, a distance l_ex on the optical axis from final lens face of the 44th group to the final lens face, and aperture diameter ea_sp when the aperture stop is opened are appropriately set. <P>COPYRIGHT: (C)2012,JPO&INPIT |
