Abstract: A fixed focal length imaging optical system includes a first lens group having positive power, a second lens group having positive power, and a third lens group having negative power in order from an object side toward an image side. Upon focusing, the second lens group moves along an optical axis, and the first lens group and the third lens group do not move. The present disclosure provides the fixed focal length imaging optical system capable of favorably correcting various aberrations such as spherical aberration, astigmatism, and distortion, and an imaging device and a camera system each of which includes the fixed focal length imaging optical system.

Abstract: A zoom lens system 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, a fourth lens unit having negative optical power, and a fifth lens unit having positive optical power, wherein the third lens unit includes at least one lens element having positive optical power and at least one lens element having negative optical power, at least the first to third lens units are moved along an optical axis in zooming so that air spaces between the respective lens units vary, thereby performing magnification change, a lens unit positioned on the image side relative to an aperture diaphragm is moved along the optical axis in focusing, and the conditions: 8.1<fG1/Ir<10.4 and Z=fT/fW?9.

Abstract: A zoom lens system, in order from an object side to an image side, comprising a positive first lens unit, a negative second lens unit, a positive third lens unit, and a positive fourth lens unit, wherein the first lens unit is composed of a cemented lens element of one object side negative lens element and one image side positive lens element, the fourth lens unit is composed of one lens element, in zooming, the first to fourth lens units are individually moved along an optical axis so that air spaces between the respective lens units vary for magnification change, and the conditions: vdL12<43.50 and fT/fW?6.0 (vdL12: an Abbe number of the positive lens element in the first lens unit, fT and fW: focal lengths of the entire system at a telephoto limit and a wide-angle limit) are satisfied; an imaging device; and a camera.

Abstract: A zoom lens system 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, a fourth lens unit having negative optical power, and a fifth lens unit having positive optical power, wherein the third lens unit includes at least one lens element having positive optical power and at least one lens element having negative optical power, at least the first to third lens units are moved along an optical axis in zooming so that air spaces between the respective lens units vary, thereby performing magnification change, a lens unit positioned on the image side relative to an aperture diaphragm is moved along the optical axis in focusing, and the conditions: 4.0<D/Ir<5.3 and Z=fT/fW?9.

Abstract: A zoom lens system, in order from an object side to an image side, comprising a positive first lens unit, a negative second lens unit, a positive third lens unit, and a positive fourth lens unit, wherein the first lens unit is composed of a cemented lens element of one object side negative lens element and one image side positive lens element, the fourth lens unit is composed of one lens element, in zooming, the first to fourth lens units are individually moved along an optical axis so that air spaces between the respective lens units vary for magnification change, and the conditions: vdL12<43.50 and fT/fW?6.0 (vdL12: an Abbe number of the positive lens element in the first lens unit, fT and fW: focal lengths of the entire system at a telephoto limit and a wide-angle limit) are satisfied; an imaging device; and a camera.

Abstract: A zoom lens system 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, a fourth lens unit having negative optical power, and a fifth lens unit having positive optical power, wherein the third lens unit includes at least one lens element having positive optical power and at least one lens element having negative optical power, at least the first to third lens units are moved along an optical axis in zooming so that air spaces between the respective lens units vary, thereby performing magnification change, a lens unit positioned on the image side relative to an aperture diaphragm is moved along the optical axis in focusing, and the conditions: 8.1<fG1/Ir<10.4 and Z=fT/fW?9.

Abstract: A zoom lens system 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, a fourth lens unit having negative optical power, and a fifth lens unit having positive optical power, wherein the third lens unit includes at least one lens element having positive optical power and at least one lens element having negative optical power, at least the first to third lens units are moved along an optical axis in zooming so that air spaces between the respective lens units vary, thereby performing magnification change, a lens unit positioned on the image side relative to an aperture diaphragm is moved along the optical axis in focusing, and the conditions: 4.0<D/Ir<5.3 and Z=fT/fW?9.