To provide a variable power optical system in which aberration fluctuation during power variation is suppressed, ghost and flare are further reduced, and excellent optical performance is achieved from the wide angle state to the telephoto state.
The variable power optical system comprises, in order from the object side: a positive first group G1; a negative second group G2; a positive third group G3; and a positive fourth group G4. An antireflection film is provided on at least one surface among the optical surfaces in the first group G1 and the fourth group G4. The antireflection film comprises at least one layer which is formed by wet process. When varying power from the wide angle state to the telephoto state, the position of the first group G1 in the optical axis direction is fixed, and at least the second group G2 and the third group G3 are moved in the optical axis direction so that the distance between the first group G1 and the second group G2 is increased, and the distance between the second group G2 and the third group G3 is decreased. At least a part of the first group G1 to fourth group G4 is moved so as to include a component in a direction perpendicular to the optical axis. The variable power optical system satisfies a predetermined conditional expression.
YAMAGUCHI SATOSHI
| JP2012058620A | 2012-03-22 | |||
| JP2011197302A | 2011-10-06 | |||
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| JP2012118097A | 2012-06-21 | |||
| JP2009192996A | 2009-08-27 | |||
| JP2011113052A | 2011-06-09 |
| WO2006030848A1 | 2006-03-23 |
Kenichi Aihara
Ryuji Ito
Junko Inoue