| CPC G02B 15/145523 (2019.08) [G02B 15/143507 (2019.08); G02B 15/144515 (2019.08); G03B 5/02 (2013.01)] | 17 Claims |
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1. A zoom lens comprising a first lens unit having negative refractive power, a middle group consisting of a second lens unit having positive refractive power and a third lens unit disposed closer to an image side with respect to the second lens unit and having positive refractive power, and a last lens unit having positive refractive power that are arranged in an order from the object side to an image side,
wherein a spacing between adjacent lens units, among the lens units, changes in zooming,
wherein the zoom lens includes an aperture stop,
wherein the first lens unit includes a first negative lens, a second negative lens, and a third negative lens that are arranged in the order from the object side to the image side,
wherein a number of the negative lenses included in the first lens unit is three or four,
wherein the middle group includes a plurality of cemented lenses each having a cemented surface that is convex toward the object side, and includes a lens element Ln that is disposed closest to the image side among lens elements having negative refractive power included in the middle group, and
wherein the following inequalities are satisfied:
1.2<|f1|/fw<2.0,
0.5<L1s/Lsn<1.8, and
0.7<|fn|/Lsn<2.0,
where f1 is a focal length of the first lens unit, fw is a focal length of the zoom lens at a wide angle end, L1s is a distance on an optical axis from a lens surface, of the zoom lens, disposed closest to the object side to the aperture stop at the wide angle end, Lsn is a distance on the optical axis from the aperture stop to a lens surface, of the lens element Ln, disposed closest to the image side at the wide angle end, and fn is a focal length of the lens element Ln.
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