| 摘要 |
PROBLEM TO BE SOLVED: To obtain a four-group constitution zoom lens having a high zoom ratio of >=8 which is suitable for a digital camera using an imaging device with one million or more pixels, and to obtain optical equipment using the zoom lens. SOLUTION: As for the zoom lens provided with a 1st group which is fixed at zooming and focusing, and having a positive refractive power, a 2nd group having a zooming function and a negative refractive power, a 3rd group having a positive refractive power and a 4th group having a function of correcting an image field which is shifted at zooming and also a focusing function and having a positive refractive power, in this order from an object side, and the 1st group is constituted of a doublet constituted of a negative lens and a positive lens, and two meniscus positive lenses whose convex surfaces face the object side, in this order from the object side, and the 2nd group is provided with at least three negative lenses and one positive lens. |
