| 摘要 |
Disclosed is an image position correcting optical system, comprising, sequentially from an object side, a first lens group having positive refracting power and a second lens group having negative refracting power. The first lens group is fixed. The second lens group is so provided as to be movable along an optical axis. A part of lens subunits of lens elements constituting the first lens group is so provided as to be movable in a direction across the optical axis. A positive lens element of the lens elements constituting the first lens group satisfies the following conditions: <IMAGE> where nd is the refractive index with respect to the d-line, nF is the refractive index with respect to the F-line, nC is the refractive index with respect to the C-line, nu d is the Abbe number with respect to the d-line, and theta FCd is the partial dispersion ratio expressed by (nd-nC)/(nF-nC).
|
