PURPOSE: To compensate aberrations and curvature of field while keeping the balance, to make the lens comparatively bright am to take close-up photography by comprising a first to a third lens groups having specified refractive powers and extending the first and the second lens groups to the object side from the fixed third lens group.

CONSTITUTION: This lens is composed, in order from the object side, of a first to a third lens groups G1-G3 having positive refractive powers and the first and the second lens groups G1, G2 are, extended the object side opposite to the third lens group G3 fixed on the image plane at the time of focusing from an object at infinity to an object at a short distance. The conditional relations : 0.8<1/1MOD<1.8, 0.5<2/<1.5, 0.5<β3<1.5 are satisfied. In the relations, , 1, 2 are refractive powers of the whole system, the first lens group G1 and the second lens group G2 at the time of focusing at infinity, respectively, 1MOD is the refractive power of the first lens group at the time of focusing at the shortest distance and β3 is the magnification of the third lens group G3 at the time of focusing at infinity.