Optical system and optical apparatus having the same

摘要

An optical system includes, in order from an object side to an image side, a front unit having a positive refractive power, an aperture diaphragm, and a rear unit. The front unit includes a first lens unit having a positive refractive power. The rear unit includes a second unit adjacent to the aperture diaphragm and configured to move in focusing. The first lens unit includes n (which is an integer of 2 or higher) positive lenses and one or more negative lenses. The materials of at least two positive lenses of the n positive lenses in the first lens unit satisfy 0.0100<ΔθgF where ΔθgF is an abnormal partial dispersion of each material. The material of one or more positive lenses of the n positive lenses in the first lens unit satisfies 0.0272<ΔθgF. Additional conditional expressions are satisfied.

主权项

1. An optical system comprising, in order from an object side to an image side, a front unit having a positive refractive power, an aperture diaphragm, and a rear unit,
wherein the front unit includes a first lens unit having a positive refractive power, the rear unit includes a second lens unit adjacent to the aperture diaphragm and configured to move in focusing, and the first lens unit includes n (which is an integer equal to or larger than 2) positive lenses and one or more negative lenses, wherein materials of at least two positive lenses of the n positive lenses in the first lens unit satisfy the following conditional expression:
0.0100<ΔθgF where ΔθgF is an abnormal partial dispersion of each material, wherein the material of one or more positive lenses of the n positive lenses in the first lens unit satisfies the following conditional expression:
0.0272<ΔθgF wherein the following conditional expressions are satisfied:
0.15