| 摘要 |
A zoom lens system is provided with first, second, and third lens units from an enlargement side. The first, second, and third lens units have a negative refractive power, positive refractive power, and negative refractive power, respectively. The first lens unit has a first doublet lens composed by a biconvex lens and a biconcave lens. The second lens unit has a second doublet lens composed by a biconvex lens and a negative meniscus lens. During zooming from the longest focal length end to the shortest focal length end, the first lens unit is kept stationary and the second and third lens units are each moved monotonically.
|
