Zoom lens system

A zoom lens system according to claim I wherein said third lens group satisfies the following condition (c):

• m3L<-m3S<-1.0 (c)
• where
• m3L=the magnification by the third lens group at the telephoto end;
• and
• m3S:
• the magnification by the third lens group at the wide-angle end.

A zoom lens system comprising, in order from the object side, a first lens group having a positive power, a second lens group having a negative power and a third lens group having a positive power, said first lens group being fixed during zooming, said second and third lens groups being moved along the optical axis as zooming is effected, said system satisfying the following conditions (a) and (b)

• 0.8<fW/.function.1<1.25 (a)
• m2L<-1<m2S (b)
• where
• fW is the focal length of the overall system a the wide-angle end;
• .function.1 is the focal length of the first lens group;
• m2L is the magnification by the second lens group at the telephoto end;
• and
• m2S is the magnification by the second lens group at the wide-angle end;
• said third lens group satisfies the following condition (c):
• m3L<m3S<-1.0 (c)
• where
• m3L is the magnification by the third lens group at the telephoto end;
• and
• m3S is the magnification by the third lens group at the wide-angle end.

A zoom lens system comprising, in order from the object side, a first lens group having a positive power, a second lens group having a negative power and a third lens group having a positive power, said first lens group being fixed during zooming, said second and third lens groups being moved along the optical axis as zooming is effected, said system satisfying the following conditions (a), (b) and (c):

• 0.8<fW/.function.1<1.25
• m2L<-1<m2S
• 80<v1p
• where v1p is the greatest value of the Abbe numbers of the positive lenses in the first lens group,
• where fW is the focal length of the overall system a the wide-angle end;
• where .function.1 is the focal length of the first lens group;
• where m2L is the magnification by the second lens group at the telephoto end;
• and
• m2S is the magnification by the second lens group at the wide-angle end.

A zoom lens system comprising, in order from the object side, a first lens group having a positive power, a second lens group having a negative power and a third lens group having a positive power, said first lens group being fixed during zooming, said second and third lens groups being moved along the optical axis as zooming is effected, said system satisfying the following conditions (a) and (b):

• 0.8<fW/.function.1<1.25 (a)
• m2L<-1<m2S (b)
• where
• fW is the focal length of the overall system a the wide-angle end;
• .function.1 is the focal length of the first lens group;
• m2L is the magnification by the second lens group at the telephoto end;
• and
• m2S is the magnification by the second lens group at the wide-angle end;
• said third lens group comprises, in order from the object side, a positive first sub-group 3a and a negative second sub-group 3b and satisfies the following condition (c):
• 8<
• v3p (c)
• where v3p is the Abbe number of the positive lens in the sub-group 3a.

A zoom lens system comprising, in order from the object side, a first lens group having a positive power, a second lens group having a negative power and a third lens group having a positive power, said first lens group being fixed during zooming, said second and third lens groups being moved along the optical axis as zooming is effected, said system satisfying the following conditions (a) and (b):

• 0.8<fW/<1<1.25 (a)
• m2L<-1<m2S (b)
• where
• fw is the focal length of the overall system a the wide-angle end;
• .function.1 is the focal length of the first lens group;
• m2L is the magnification by the second lens group at the telephoto end;
• and
• m2S is the magnification by the second lens group at the wide-angle end;
• said third lens group comprises, in order from the object side, a sub-group 3a having a positive power and a sub-group 3b having a negative power, with the distance between said sub-groups 3a and 3b being varied as zooming is effected.