| 摘要 |
PROBLEM TO BE SOLVED: To obtain a rear focus type zoom lens and a camera using the zoom lens which is provided with four lens groups as a whole, where focusing is performed by the lens group positioned backward from a variable power system, which has such a wide viewing angle that its photographing viewing angle is >=65 deg. and whose variable power ratio is high. SOLUTION: This lens is provided with four lens groups, that is, the 1st group L1 having positive refractive power, the 2nd group L2 having negative refractive power, the 3rd group L3 having positive refractive power and the 4th group L4 having positive refractive power in order from an object side. In the case of varying power from a wide-angle end to a telephoto end, the 2nd lens group L2 is moved to an image surface side and the 3rd and the 4th groups L3 and L4 are also moved, and in the case of focusing, the 4th group L4 is moved. The 2nd group L2 is constituted of three single lenses, that is, a 21st negative lens whose concave surface having stronger refractive power faces to the image surface side than the object side, a 22nd negative lens whose both surfaces are concave and a 23rd positive lens whose concave surface faces to the object side. |
