| 摘要 |
<p>A zoom lens system, including, in order from an object side: a first unit having a positive refractive power; a second unit having a negative refractive power that moves for magnification-varying; a third unit having one of a positive refractive power and a negative refractive power that moves for magnification-varying; and a fourth unit having a positive refractive power, in which: when an Abbe constant of a positive lens Lp having a smallest Abbe constant among lenses constituting the first unit is denoted by ½p, a partial dispersion ratio thereof is denoted by ¸p, a refractive power thereof is denoted by Õp, an average value of Abbe constants of positive lenses except the positive lens Lp is denoted by ½ap, an average value of partial dispersion ratios of negative lenses of the first unit is denoted by ¸an, a refractive power of the first unit is denoted by Õ1, and a refractive power of an entire zoom lens system at a telephoto end is denoted by Õtele, the following conditional expressions are satisfied: - 0.03 < ¸p - ¸an / ¸an < 0.15 ; 0.005 < 1 / ½p - 1 / ½ap / Æ �¢ 1 / Ætele < 0.030 ; and 0.05 < Æp / Æ �¢ 1 < 0.4.</p> |
