Zoom lens system
A zoom lens system includes a first lens group of negative refractive power, a second lens group of positive refractive power and a third lens group of positive refractive power. The zoom lens system satisfies the following condition formulas: 0.78<|f 2 /f 1 |<0.91, and 0.72<L 2 /fT<0.87, where f 1 represents an effective focal length of the first lens group, f 2 represents an effective focal length of the second lens group, L 2 is a displacement of the second lens group when the zoom lens system varies from a wide-angle state to a telephoto state, and fT represents an effective focal length of the zoom lens system which is in the telephoto state.
1. A zoom lens system, in order from an object-side to an image-side thereof, comprising:
a first lens group of negative refractive power, the first lens group comprising, in the order from the object-side to the image-side of the zoom lens system, a first lens of negative refractive power and a second lens of positive refractive power;
a second lens group of positive refractive power, the second lens group comprising, in the order from the object-side to the image-side of the zoom lens system, a third lens of positive refractive power, a fourth lens of positive refractive power, a fifth lens of negative refractive power, and a sixth lens of negative refractive power; and
a third lens group of positive refractive power;
the zoom lens system satisfying the following condition formulas:
0.78 <|f 2 /f 1|<0.91, and
0.72 <L 2 /fT< 0.87,
where f 1 represents an effective focal length of the first lens group, f 2 represents an effective focal length of the second lens group, L 2 is a displacement of the second lens group when the zoom lens system varies from a wide-angle state to a telephoto state, and fT represents an effective focal length of the zoom lens system which is in the telephoto state.
2. The zoom lens system of claim 1 , wherein the zoom lens system satisfies the following condition formula: 1.75<V 1 /V 2 <2.45, where V 1 , V 2 are Abbe numbers of the first lens and the second lens in d light, respectively.
3. The zoom lens system of claim 1 , wherein the third lens comprises at least one aspherical surface.
4. The zoom lens system of claim 1 , wherein the sixth lens is a plastic lens.
5. The zoom lens system of claim 1 , wherein the fourth lens and the fifth lens are combined together.
6. The zoom lens system of claim 1 , wherein the third lens group comprises a seventh lens of positive refractive power.
7. The zoom lens system of claim 1 , wherein the zoom lens system satisfies the following condition formula: 0.28<f 2 /f 3 <0.5, where f 3 represents an effective focal length of the third lens group.
8. The zoom lens system of claim 1 , further comprising an aperture stop positioned between the second lens group and the third lens group.