| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a compact high variable power zoom lens that has a larger zoom ratio of at least 15-power and at least 75-degree field angle at a wide angle end and is suitable for an APS size single-lens reflex camera. <P>SOLUTION: A high variable power zoom lens comprises, from an object side to an image surface side, a first lens group G1 of positive refractive power, a second lens group G2 of negative refractive power, a third lens group G3 of positive refractive power and a fourth lens group G4 of positive refractive power. The high variable power zoom lens satisfies conditional expression (1) 12<Lt/(Ft/Fw)<15, in which Lt represents an entire optical length at a telephoto end (length from a lens surface closest to the object side to the image surface side), Ft represents a focal length of an entire optical system at the telephoto end, and Fw represents a focal length of the entire optical system at a wide angle end. <P>COPYRIGHT: (C)2012,JPO&INPIT |
