Optical system and optical apparatus

摘要

The optical system includes first (positive) and second (negative) lens units arranged in order from an object side to an image side, and an aperture stop disposed further on the image side than the second lens unit. The first lens unit includes at least one first optical element satisfying φGH>0.0, νdGH<39.5 and ndGH>1.70. The optical system satisfies 0.65<|φ2/φ1|<6.00 and 0.45<|ΣφGH×φ2/φ12|<4.00. φGH represents a refractive power of the first optical element when light-entrance and light-exit surfaces thereof are in contact with air, νdGH and ndGH respectively represent an Abbe number and a refractive index of a material forming the first optical element for a d-line, φ1 and φ2 respectively represent the refractive powers of the first lens unit and the second lens unit, and ΣφGH represents a sum total of the refractive power φGH of the at least one first optical element.

主权项

1. An optical system comprising:
a first lens unit and a second lens unit that are arranged in order from an object side to an image side, the first lens unit having a positive refractive power and the second lens unit having a negative refractive power; and an aperture stop disposed further on the image side than the second lens unit, wherein during focusing, the first lens unit is not moved with respect to an image plane in an optical axis direction and the second lens unit is moved with respect to the image plane in the optical axis direction, wherein none of lenses included in the first lens unit are moved with respect to each other during the focusing, and wherein the first lens unit includes at least one first optical element satisfying the following conditions:
φGH>0.0;νdGH<39.5; andndGH>1.70, and wherein the optical system satisfies the following conditions:
βmax>0.5;0.65<|φ2/φ1|<1.8;0.45<|ΣφGH×φ2/φ12|<4.00; and0.28<|ΣφGH/φ1/βmax|<3.0, where φGH represents a refractive power of the first optical element when a light-entrance surface and a light-exit surface of the first optical element are in contact with air, νdGH and ndGH respectively represent an Abbe number and a refractive index of a material forming the first optical element for a d-line, βmax represents a maximum image-forming magnification of the optical system, φ1 and φ2 respectively represent the refractive powers of the first lens unit and the second lens unit, and ΣφGH represents a sum total of the refractive power φGH of the at least one first optical element.