| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens that is suitable for a video camera or an electronic still camera using a solid state image sensor, has larger variable magnification ratio compared to conventional lenses, and has reduced size, ultra-high image quality, and high magnification; an optical device; and a manufacturing method of the zoom lens.SOLUTION: A zoom lens comprises: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; and a fourth lens group G4 having a positive refractive power. The first lens group G1 is configured only by a cemented lens of a negative lens L11 and a positive lens L12, which are arranged in order from an object side, and a positive meniscus lens L13 with a convex face oriented to the object side; and an aperture diaphragm S for determining brightness is arranged on the object side of the third lens group G3. In zooming, when all the four groups G1 to G4 move; the aperture diaphragm S moves integrally with the third lens group G3; and the Abbe number with a d-line of the positive lens L12 arranged on the most object side of the first lens group G1 as a standard is dp1, the conditional expression &ngr;dp1>85.0 is satisfied. |
