Compact zoom lens system having high zoom ratio and wide view angle

摘要

A compact zoom lens system suitable for use with a compact camera or the like, which has a view angle of 70° or more at the wide end and a zoom ratio of 2.5 or higher and in which various aberrations, particularly field curvature, distortion, axial and lateral chromatic aberrations, are effectively corrected over the entire zoom range, from the wide end to the tele end. The zoom lens system comprises, in order from the object side, a negative 1-st lens unit (G1), a positive 2-nd lens unit (G2), a positive 3-rd lens unit (G3), and a negative 4-th lens unit (G4). During zooming from the wide end to the tele end, the 1-st and 3-rd lens units (G1) and (G3) move together as one unit toward the object side, while the 4-th lens unit moves toward the object side so that the spacing between the same and the 3-rd lens unit (G3) monotonously decreases. Meantime, the 2-nd lens unit (G2) moves so that, during its movement from the wide end to the middle focal length position, it approaches the 1-st lens unit (G1), whereas, during its movement from the middle focal length position to the tele end, the 2-nd lens unit (G2) approaches the 3-rd lens unit (G3).