Zoom lens and image pickup apparatus including the same

摘要

A zoom lens includes, from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, an aperture stop, a third lens unit having a positive refractive power, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power. During zooming, the first lens unit and the aperture stop do not move and the second, third, and fourth lens units move along different loci. Lateral magnifications of the second lens unit at a wide angle end and at a telephoto end and lateral magnifications of the third lens unit at the wide angle end and at the telephoto end are each appropriately set based on predetermined mathematical conditions.

主权项

1. A zoom lens comprising, from an object side to an image side:
a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; an aperture stop; a third lens unit having a positive refractive power; a fourth lens unit having a negative refractive power; and a fifth lens unit having a positive refractive power, wherein, during zooming, the first lens unit and the aperture stop do not move, and the second, third, and fourth lens units move along different loci, and wherein the zoom lens satisfies a conditional expression
0.8<(β2t/β2w)/(β3t/β3w)<5.0, where β2w and β2t are respectively lateral magnifications of the second lens unit at a wide angle end and at a telephoto end, and β3w and β3t are respectively lateral magnifications of the third lens unit at the wide angle end and at the telephoto end.