| 摘要 |
<p>A zoom lens system including, from the object side to the image side, a first lens unit and a second lens unit, where when zooming, the distance between the first lens unit and the second lens unit changes. In at least one exemplary embodiment, the first lens unit includes a first lens element having negative optical power, and a second lens element having positive optical power.
A zoom lens system comprising from the object side to the image side: a negative optical power first lens unit comprising a negative optical power first lens element and a positive optical power second lens element; and a positive optical power second lens unit. The distance between the first and second lens units changes during zooming. In a first embodiment, the focal lengths f1, f11, f12 of respective first lens unit and the first and second lens elements satisfy the condition -0.6 < ((f11 x f12)/f1 2 ) < - 0.2, and Abbe numbers v11 and v12 of respective materials of the first and second lens elements, satisfy the condition 7 < (v11 - v12) < 15. In a second embodiment, the refractive index N12 and the Abbe number v12 satisfy the conditions 1.8 < N12 and 26 < v12.</p> |
