| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a zoom lens having a high zooming ratio which is capable of focusing without an extreme increase in amount of movement of a focus group when focusing over a total object distance. <P>SOLUTION: The zoom lens includes: a first lens group with positive refractive power; a second lens group with negative refractive power; a third lens group with negative refractive power; and a rear group with positive refractive power as a whole including a plurality of lens groups, in this order from the object side to the image side, and the distances between respective lens groups vary when zooming. In the zoom lens, the third lens group is moved when focusing. A focal distance fw of a total system in a wide angle end, a focal distance ft of a total system in a telephoto end, a synthetic focal distance f12w of the first lens group and the second lens group in the wide angle end and a synthetic focal distance f12t of the first lens group and the second lens group are respectively set suitably. <P>COPYRIGHT: (C)2013,JPO&INPIT |
