| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which comprises a compact lens system, has a wide view angle, and easily provides superior optical performance over an entire zoom range.SOLUTION: A zoom lens comprises first, second, and third lens groups having negative, positive, and negative refractive power, respectively, and is configured to move each of the lens groups while zooming such that a distance between each pair of adjacent lens groups changes. The first lens group has one or more each of negative lenses and positive lenses, and the second lens group has one or more positive lenses. A refractive index nF of a material at a wavelength of 486.13 nm, a refractive index nd of the material at a wavelength of 587.6 nm, a refractive index nC of the material at a wavelength of 656.27 nm, a refractive index nt of the material at a wavelength of 1013.98 nm, an Abbe number νd, a partial dispersion ratio θCt, an Abbe number νdA of a material of a positive lens A, a partial dispersion ratio θCtA, a focal length f1 of the first lens group, and a focal length fw of the entire system at the wide-angle end are each set appropriately.SELECTED DRAWING: Figure 1 |
