| 摘要 |
An optical system includes a first lens unit fixed during a focusing operation and having a positive refractive power, a second lens unit moving in an optical axis direction during the focusing operation and having a negative refractive power, a third lens unit positioned at the image side relative to the second lens unit and having a positive or negative refractive power, the first lens unit is configured by first, second, and third partial lens units, the first partial lens unit is configured by two positive lens components, the second partial lens unit is configured by one cemented lens having a negative combined refractive power, the third partial lens unit is positioned between the second partial lens unit and the second lens unit and has a positive refractive power as a whole, and each lens unit is configured so as to meet an appropriate condition. |
