Image pickup optical system and image pickup apparatus including the same

Abstract

Provided is an optical system including, in order from object side to image side, a positive first lens unit (LU), a positive second LU and a third LU, in which intervals between adjacent LUs are changed during focusing. The second LU moves toward object side during focusing from infinity to the closest distance. In order from object side to image side, second LU includes at least one positive lens, a negative lens Ln having a meniscus shape that is concave toward image side, an aperture stop, and a cemented lens consisting of a plurality of lenses and an optical element Gp cemented to one another and having a concave lens surface on object side, then third LU includes a positive lens and a negative lens. A refractive index of a material of Ln with respect to d-line and a partial dispersion characteristic of a material of Gp are appropriately set.