| 摘要 |
<p>The invention comprises a zoom lens system including two lens groups. The first lens group has an overall positive refractive power, and includes three sub-group lens units. The first sub-group lens unit has a negative refractive power, the second sub-group lens unit has a positive refractive power, and the third sub-group lens unit has a positive refractive power. The second lens group has an overall negative refractive power and includes two sub-group lens units. The fourth sub-group lens unit has a positive refractive power, and the fifth sub-group lens unit has a negative refractive power. The magnification of the system can be changed by varying a distance between the first lens group and the second lens group, wherein the following conditions are satisfied:Mt/Mw>1.95,0.20<fbw/fw<0.37,where: Mt represents the magnification of the second lens group at a telephoto position; Mw represents the magnification of the second lens group at a wide-angle position; fw represents a focal length of the zoom lens system at the wide-angle position; and fbw represents a back focal length of the zoom lens system at the wide-angle position.</p> |
