| 摘要 |
A zoom lens of the telephoto type comprising a first lens unit (L1) of positive refractive power, a second lens unit (L2) of negative refractive power, a third lens unit (L3) of positive refractive power, and a fourth lens unit (L4) of positive refractive power, the units being disposed in that order from object- to image-side, the second and fourth lens units (L2,L4) being moved along the optical axis of the zoom lens during zooming, characterized in that the first lens unit (L1) consists of one negative lens (G11) and three (G12,G13,G14) or fewer positive lenses, being disposed in that order from the object side to the image side, and the following condition is satisfied:
where BD1 and BD2 are the lengths of the first and second lens units (L1,L2) along the optical axis, and Z is the zoom ratio. |
