| 摘要 |
PROBLEM TO BE SOLVED: To obtain a zoom lens which utilizes negative lead type lens constitution, whose photographic viewing angle at a wide-angle end is 84 deg., whose variable power ratio is 2.9 and which has brightness that an F-number is about 2.9 in all the variable power range and has high optical performance in all the variable power range, and optical equipment using the zoom lens. SOLUTION: This zoom lens is provided with a 1st A lens group having negative refractive power, a 1st B lens group having negative refractive power, a 2nd lens group having positive refractive power, a 3rd lens group having negative refractive power and a 4th lens group having positive refractive power in order from an object side. Variable power is performed by moving the respective lens groups, and focusing from an infinity object to a short-distance object is performed by moving the 1st B lens group to the object side. Then, the synthetic focal distance f1AB of the 1st A lens group and the 1st B lens group and the focal distance (ft) of an entire system at a telephoto end are appropriately set.
|
