| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens system which has excellent optical characteristics, has fewest individual moving lens units, a relatively wide zoom range (i.e., a zoom ratio larger than 1.5), and which is smaller than the size of a zoom lens system of the prior art. SOLUTION: This lens is composed of the three lens units U1 , U2 , U3 having positive, positive and negative refracting power. The front part and rear part lens units U1 and U3 move together at the time of zooming but the intermediate lens unit U2 moves independently. One aspherical face is included in the respective three lens units. An aperture stop AS is installed together with the front part lens unit U1 . |
