Patent ID: 7031072

Claim:
A zoom lens system comprising: a first lens unit having a positive optical power; a second lens unit having a negative optical power, the second lens unit being disposed on the image side of the first lens unit and having at least one negative lens and at least one positive lens; a third lens unit having a positive optical power, the third lens unit being disposed closer to the image than the second lens unit; a fourth lens unit having a positive optical power, the fourth lens unit being disposed closer to the image than the third lens unit; and an aperture stop being disposed closer to the image than the second lens unit, wherein the distance between the first and second lens units, the distance between the second and third lens unit and the distance between the third and fourth lens unit changes during zooming of the zoom lens system, and wherein L/S< 0.85 and ν 2 p<21.9 where L represents the distance between the surface on the image side of a positive lens having the strongest optical power among positive lenses included in the second lens unit and the surface of a lens closest to the object among lenses included in the third lens unit at the telephoto end, S represents the distance between the surface on the image side of the positive lens having the strongest optical power among the positive lenses included in the second lens unit and the aperture stop at the telephoto end, and ν 2 p represents the Abbe number of the positive lens having the strongest optical power among the lenses included in the second lens unit.