| 摘要 |
<p>Zoom lens of the retrofocus type comprising a negative first lens-group (G1), a positive second lens-group (G2), a negative third lens-group (G3) and a positive fourth lens-group (G4), in that order from the object side, wherein upon zooming from the short focal-length to the long focal-length, the distance between said first (G1) and said second lens-group (G2) decreases, the distance between said second (G2) and said third lens-group (G3) increases and the distance between said third (G3) and said fourth lens- group (G4) decreases, wherein said second lens-group (G2) consists of a positive first sub-lens-group (G2a), a positive second sub-lens-group (G2b) and a third sub-lens-group (G2c), in that order from the object side, and wherein said third sub-lens-group (G2c) is a cemented doublet consisting of a negative meniscus lens (24) having a convex surface facing the object side and a positive meniscus lens (25) having a convex surface facing the object side, in that order from the object side.</p> |
