Wide-angle zoom lens system

A wide-angle zoom lens system comprises a negative first lens group, a positive second lens group, a negative third lens group and a positive fourth lens group, in this order from an object;

• wherein upon zooming from the short focal length extremity to the long focal length extremity, a distance between said negative first lens group and said positive second lens group decreases, a distance between said positive second lens group and said negative third lens group increases, and a distance between said negative third lens group and said positive fourth lens group decreases;
• wherein said wide-angle zoom lens system satisfies the following conditions:
• 0.6<f2/ft<0.8
• 0.4<|f3|/ft<0.9 (f3<0)
• wherein
• f2 designates the focal length of said positive second lens group;
• f3 designates the focal length of said negative third lens group;
• and
• ft designates the focal length of the entire wide-angle zoom lens system at the long focal length extremity.

A wide-angle zoom lens system comprises a negative first lens group, a positive second lens group, a negative third lens group and a positive fourth lens group, in this order from an object;

• wherein upon zooming from the short focal length extremity to the long focal length extremity, a distance between said negative first lens group and said positive second lens group decreases, a distance between said positive second lens group and said negative third lens group increases, and a distance between said negative third lens group and said positive fourth lens group decreases;
• wherein said wide-angle zoom lens system satisfies the following conditions:
• 1.2<f2/|f1|<1.6 (f1<0)
• 1.2<f4/|f3|<1.6 (f3<0)
• wherein
• f1 designates the focal length of said negative first lens group;
• f2 designates the focal length of said positive second lens group;
• f3 designates the focal length of said negative third lens group;
• and
• f4 designates the focal length of said positive fourth lens group.