Patent ID: 11971540
Assignee: NIKON CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An optical system comprising a glass lens satisfying the following conditional expressions:

ndLZ+(0.01425×νdLZ)<2.12

νdLZ<35.0

1.83<ndLZ+(0.00787×νdLZ)

0.702<θgFLZ+(0.00316×νdLZ)<0.800, where
ndLZ: a refractive index of the lens with reference to d-line,
νdLZ: Abbe number of the lens with reference to d-line, and
θgFLZ: a partial dispersion ratio of the lens, which is defined by the following expression:

θgFLZ=(ngLZ−nFLZ)/(nFLZ−nCLZ), wherein a refractive index of the lens with reference to g-line is ngLZ, a refractive index of the lens with reference to F-line is nFLZ, and a refractive index of the lens with reference to C-line is nCLZ.