| 摘要 |
The present invention has, arranged in order from the object side along the optical axis: a first lens group (G1) having negative refractive power; a second lens group (G2) having positive refractive power; and a third lens group (G3) having positive refractive power. The first lens group (G1) is constituted only of a single spherical surface negative lens and a single spherical surface positive lens separated by an air space. The following conditional equations (1) and (2) are satisfied. 0.40 < (DG1 + DG2 + DG3)/ft < 0.65... (1) 0.20 < (-f1)/ft < 0.60 ... (2) Here, DG1 is the thickness of the first lens group (G1) on the optical axis, DG2 the thickness of the second lens group (G2) on the optical axis, DG3 the thickness of the third lens group (G3) on the optical axis, ft the focal distance of the entire lens system at the telephoto end state, and f1 the focal distance of the first lens group (G1). |
