Wide-angle lens system

A wide-angle lens system comprises a negative front lens group, a diaphragm and a positive rear lens group, in this order from an object,

• wherein said negative front lens group comprises a negative first sub-lens group and a positive second sub-lens group, in this order from the object;
• wherein said positive rear lens group comprises cemented lens elements having a positive lens element, a negative lens element and a positive lens element;
• and
• wherein said wide-angle lens system satisfies the following conditions:
• −0.8<fla/flb<−0.2
• 0.1<d/f<0.3
• wherein
• fla designates the focal length of said negative first sub-lens group;
• flb designates the focal length of said positive second sub-lens group;
• d designates the axial distance between said negative front lens group and said positive rear lens group;
• and
• f designates the focal length of the entire wide-angle lens system.

A wide-angle lens system comprises a negative front lens group, a diaphragm and a positive rear lens group, in this order from an object,

• wherein said negative front lens group comprises a negative first sub-lens group and a positive second sub-lens group, in this order from the object;
• wherein said wide-angle lens system satisfies the following conditions:
• −15<fF/f<−1.5
• −2.0<fla/f<−0.5
• wherein
• fF designates the focal length of said negative front lens group;
• f designates the focal length of the entire wide-angle lens system;
• and
• fla designates the focal length of said negative first sub-lens group;
• wherein a focusing operation is performed by moving said negative front lens group and said positive rear lens group by different distances respectively;
• and
• wherein said wide-angle lens system satisfies the following condition:
• 0.7<X1/X2<0.94
• wherein
• X1 designates a travelling distance of said negative front lens group upon focusing;
• and
• X2 designates a travelling distance of said positive rear lens group upon focusing.