Zoom lens system, imaging device and camera

A zoom lens system comprising a plurality of lens units each composed of at least one lens element, the zoom lens system, in order from an object end to an image end thereof, comprising:

• a first lens unit having positive optical power;
• a second lens unit having negative optical power;
• a third lens unit having positive optical power;
• and
• one or more subsequent lens units, as being in an interval from the image end-ward side of the third lens unit to an image surface defining the image end of the zoom lens system;
• wherein
• in zooming from a wide-angle limit to a telephoto limit at a time of image taking, the first lens unit, the second lens unit, and the third lens unit are moved along an optical axis to perform magnification change, wherein
• two air spaces are included within the third lens unit, wherein
• the third lens unit consists of three lens elements separated from each other by the two air spaces, wherein
• the three lens elements constituting the third lens unit are, in order from the object end to the image end, a lens element having positive optical power, a cemented lens element having optical power, and a lens element having optical power, wherein a part of the third lens unit is a third-b lens unit that moves in a direction perpendicular to the optical axis to optically compensate image blur, and wherein the following conditions (2) and (3) are satisfied:
• 1.5<(D2+D3b+DB)/Ir<2.4 (2)
• BF/Ir<1.45 (3)
• where,
• D2 is an optical axial thickness of the second lens unit,
• D3b is an optical axial thickness of the third-b lens unit,
• DB is the aggregate sum of the optical axial thicknesses of the one or more subsequent lens units in the interval from the image end-ward side of the third lens unit to the image surface,
• BF is a shortest optical axial distance that is converted with air, between an apex of a most image side lens surface and the image surface,
• Ir is a value represented by the following equation:
• Ir=fT ×tan(ωT),
• fT is a focal length of the zoom lens system at a telephoto limit,
• fW is a focal length of the zoom lens system at a wide-angle limit, and
• ωT is a half view angle (°) at a telephoto limit.