| 摘要 |
A zoo comprises, in order from the object side, a first lens group having a positive refractive power that moves along the optical axis for focusing, a second lens group having a negative refractive power that moves along the optical axis for zooming, a third lens group having a negative refractive power that moves along the optical axis for compensating for the image plane that varies upon zooming, and a fixed, imaging fourth lens group having a positive refractive power. The fourth lens group has an aperture and comprises a first sub-group having a positive refractive power and a second sub-group having a positive refractive power, which fourth lens group further satisfies certain conditions.
|
