| 摘要 |
PROBLEM TO BE SOLVED: To provide an inner focus type macro lens where, on focusing, the swift performance of the driving of lens groups is achievable, and photographing magnification is large than 0.45 times in absolute value, and which has a half angle of view satisfying about 20 degrees, in which various aberrations are satisfactorily rectified, and which can have a vibration-proof function as well. SOLUTION: The inner focus type macro lens is composed, in the order from the object side, of a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power; and a fourth lens group having negative refractive power, and, when focusing is performed from an infinity object to a short-distance object, the first lens group and the fourth lens group are fixed to the image plane, when the second lens group move to the image plane side, simultaneously, the third lens group is moved to the object side, part or the whole of any lens group is moved almost to the vertical direction to an optical axis, an image can be moved almost in the direction vertical to the optical axis, and prescribed conditional expression is satisfied. COPYRIGHT: (C)2011,JPO&INPIT |
