| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which is sufficiently wide-angle with a half view angle of no less than 38 degrees at the wide angle end, and yet offers a magnification ratio of no less than 7x, an F-number of less than 3 at the wide angle end, resolving power compatible with image sensors with 10 to 15 million pixels, and a compact size.SOLUTION: A zoom lens includes a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power arranged in order from the object side. The first lens group G1 comprises a negative lens and a positive lens cemented together, and the second lens group G2 comprises a first negative lens, a second negative lens, and a positive lens. A ratio of a distance along the optical axis between the first lens group G1 and the second lens group G2 at the wide angle end and a distance along the optical axis between the first lens group G1 and the second lens group G2 at a zoom position at which the total length becomes minimum is set within an appropriate range. |
