Abstract: A zoom lens includes, from the object side, a positionally-fixed first lens group having a positive refracting power, a second lens group having a negative refracting power and movable in an optical axis direction for zooming, a third lens group having a positive refracting power, and a fourth lens group movable in the optical axis direction. The first lens group includes a negative lens, a positive lens and another positive lens disposed in order from the object side and satisfies 15.0<ft/fw<31.0??(1) 7.0<f1/fw<13.0??(2) ?8.5<fL1/fw<?4.0??(3) where fw and ft are the focal lengths of the entire lens system in a wide angle end state and a telephoto end state, respectively, f1 is the focal length of the first lens group, and fL1 is the focal length of the negative lens of the first lens group.

Abstract: An inner focus type zoom lens includes a first lens group that has positive refracting power and is normally located at a fixed position, a second lens group that has negative refracting power and is movable in an optical axis direction for zooming, a third lens group that has positive refracting power, a fourth lens group that is movable for correction of a focal position due to the zooming and for focusing, and a fifth lens group that has positive refracting power, in order from an object side, wherein the first lens group includes a negative lens, a first positive lens, and a second positive lens arranged in order from the object side, wherein a first face of the negative lens has a shape of a concave surface turned on the object side, and wherein the zoom lens satisfies the following conditional equation (1) ?10.0<G1R1/fw<?3.0.

Abstract: An inner focus type zoom lens includes a first lens group that has positive refracting power and is normally located at a fixed position, a second lens group that has negative refracting power and is movable in an optical axis direction for zooming, a third lens group that has positive refracting power, a fourth lens group that is movable for correction of a focal position due to the zooming and for focusing, and a fifth lens group that has positive refracting power, in order from an object side, wherein the first lens group includes a negative lens, a first positive lens, and a second positive lens arranged in order from the object side, wherein a first face of the negative lens has a shape of a concave surface turned on the object side, and wherein the zoom lens satisfies the following conditional equation (1) ?10.0<G1R1/fw<?3.0.