| 摘要 |
<p>[Problem] To achieve high optical performance in a variable magnification optical system while achieving small size and light weight. [Solution] This variable magnification optical system comprises, along the optical axis (Z) and in order from the object side: a first lens group (G1) that is fixed when the magnification is varied and that has a positive refractive power; a second lens group (G2) that has a negative refractive power; a third lens group (G3) that has a negative refractive power; a fourth lens group (G4) that has a negative refractive power; an aperture stop (St) that is fixed when the magnification is varied; and a fifth lens group (G5) that is fixed when the magnification is varied and that has a positive refractive power. When the magnification is varied from the wide-angle end to the telephoto end, the second lens group (G2), the third lens group (G3), and the fourth lens group (G4) are moved such that, compared to when the system is at the wide-angle end, the distance between the first lens group (G1) and the second lens group (G2) always widens, the distance between the second lens group (G2) and the third lens group (G3) always widens, the distance between the third lens group (G3) and the fourth lens group (G4) changes, and the distance between the fourth lens group (G4) and the fifth lens group (G5) changes.</p> |
