Patent ID: 7821723

Claim:
A high power zoom lens system comprising, in order from an object side: a first lens group that has a positive refractive power and remains stationary during zooming; a second lens group that has a negative refractive power and moving during zooming; a third lens group and a fourth lens group that respectively have a positive refractive power and are movable relative to each other to correct image plane variation accompanied by zooming; and a fifth lens group that has a positive refractive power and including a stop, the fifth lens group being used to form an image, wherein a composite lens group is formed by combining the third lens group and the fourth lens group, the second lens group and the composite lens group pass simultaneously through −1× magnification points of the respective groups during zooming from a wide-angle end to a telephoto end, and the fourth lens group has at least one aspheric surface.