Zoom lens system and optical apparatus using the same

A zoom lens system, comprising:

• a front lens component including, in order from the object side,
• a first lens unit of positive refractive power,
• a second lens unit of positive or negative refractive power,
• a third lens unit of negative refractive power, and
• a fourth lens unit of positive refractive power,
• wherein during zooming from a wide-angle end to a telephoto end, a separation between the first and second lens units keeps constant or increases, a separation between the second and third lens units increases, and a separation between the third and fourth lens units changes;
• and
• a rear lens component, wherein said rear lens component including, in order from the object side, a lens unit A of positive refractive power, a lens unit B of negative refractive power movable so as to have a component in a direction perpendicular to an optical axis for displacing the image, and a lens unit C of positive refractive power, the image being displaced as the lens unit B moves so as to have the component in the direction perpendicular to an optical axis.

A zoom lens system comprising, in order from an object side:

• a front lens component including a plurality of lens units that includes a lens unit movable for zooming and a lens unit movable for focusing,
• wherein said front lens further including, a first lens unit of positive refractive power, a second lens unit of positive or negative refractive power, a third lens unit of negative refractive power, and a fourth lens unit of positive refractive power,
• wherein during zooming from a wide-angle end to a telephoto end, a separation between the first and second lens units keeps constant or increases, a separation between the second and third lens units increases, and a separation between the third and fourth lens units changes;
• and
• a rear lens component unit, wherein said rear lens component including, in order from the object side, a lens unit A of positive refractive power, a lens unit B of negative refractive power movable so as to have a component in a direction perpendicular to an optical axis for displacing the image, and a lens unit C of positive refractive power, the image being displaced as the lens unit B moves so as to have the component in the direction perpendicular to an optical axis, wherein conditions −2.5<(f5A)/(f5B)<−1.0, −2.5<(f5C)/(f5B)<−1.0, and −1.0<(f5B)/(fw)<−0.1 are satisfied where (f5A), (f5B), and (f5C) are focal lengths of said lens units A, B and C, respectively, and (fw) is a focal length of an entire lens system at wide-angle end.

A zoom lens system comprising, in order from an object side;

• a front lens component including four lens units, each separation among said four lens units being variable during zooming;
• and
• a rear lens component including, in order from the object side, a lens unit A of positive refractive power, a lens unit B of negative refractive power movable so as to have a component in a direction perpendicular to an optical axis for displacing, the image, and a lens unit C of positive refractive power,
• wherein none of the lens units A, B and C move along the optical axis for zooming.