| 摘要 |
PROBLEM TO BE SOLVED: To obtain a light-weight and compact zoom lens constituted so that brightness and peripheral light quantity ratio are sufficiently secured, coma flare is reduced and contrast and resolution are made high by correcting the fluctuation of an image position caused by a variable power action by moving a third lens group on an optical axis. SOLUTION: This zoom lens is provided with a first lens group G1 to a fifth lens group G5. Then, the fluctuation of the image position caused by the variable power is corrected by moving the third lens group G3 along an optical axis. At this time, the conditions of 0.2<|(e4)/f4+f5)|<0.7, 0.3<|f3/f4|<0.7, 0.35<|f2/fw|<0.65, 1<υ3p/υ3n and 1.0<|f3n/f3p|2.5 are satisfied. In the expression, (e4) is an interval between the main points of the fourth lens group G4 and the fifth lens group g5, (f2)-(f5) are the focal distances of the second to the fifth lens groups G2-G5 and (fw) is the focal distance of the whole lens system at a wide-angle end. Besides,υ3n andυ3p are the average values of the Abbe number of lenses constituting a front and a rear groups G31 and G32 and f3n and f3p represents the focal distances of the front and the rear groups G31 and G32.
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