| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lens system in which various aberrations are satisfactorily rectified, and which has high optical performance reduced in ghosts and flares, and also to provide an optical device having it. <P>SOLUTION: In the lens system, a first lens group G1 and a second lens group G2 having positive refractive power are provided in order from an object side along an optical axis. The first lens group G1 is composed of an eleventh sublens group GS11 having positive refractive power and a twelfth sublens group GS12 having negative refractive power. The twelfth sublens group GS12 has a meniscus-shaped lens having a convex turned to the object side, and satisfies prescribed conditions. An antireflection film is formed on at least one side of the optical surfaces in the first lens group G1 and the second lens group G2. The antireflection film includes at least one layer formed by using a wet process. <P>COPYRIGHT: (C)2011,JPO&INPIT |
