Patent ID: 11966032
Assignee: NIKON CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A variable magnification optical system comprising, in order from an object side, a first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having negative refractive power and a fourth lens group having positive refractive power;
upon varying a magnification, a distance between the first lens group and the second lens group being varied, a distance between the second lens group and the third lens group being varied, and a distance between the third lens group and the fourth lens group being varied;
the first lens group consisting of, in order from the object side, a negative lens and a positive lens;
the second lens group consisting of, in order from the object side, a 2a lens group having positive refractive power, a 2b lens group having positive refractive power, and a 2c lens group having negative refractive power; and
the following conditional expression being satisfied:

0.50<(−f3)/fw<3.00

where f3 denotes a focal length of the third lens group, and fw denotes a focal length of the variable magnification optical system as a whole in the wide angle end state.