Abstract: A zoom lens wherein the image plane movement upon lens shifting is minimized. A power variation section and a final lens group are disposed in order from an object side. The power variation section includes at least two lens groups movable in an optical axis direction to vary a lens position state. The final lens group is fixed in the optical axis direction and includes first to third sub groups having negative, positive and positive refracting powers and disposed in order from the object side. The second sub group is shiftable substantially perpendicularly to the optical axis to shift an image. A conditional expression 0.2<ft/fBt<0.8 is satisfied where ft and fBt are the focal distances of the lens system and entire lens groups disposed on the object side of the third sub group in the telephoto end state.

Abstract: A varifocal zoom lens includes: a first lens group having a negative refractive power; a second lens group having a positive refractive power, including a cemented lens component L21 formed by combining a positive lens having a convex surface on the object side and a negative lens having a concave surface on an image side and a positive lens component L22 disposed on the image side with respect to the cemented lens component L21, spaced from the cemented lens component L21 by an air space and having a convex surface on the object side and disposed behind the first lens group with respect to an object side; and a third lens group having a positive refractive power and disposed behind the second lens group with respect to the object side.

Abstract: A varifocal zoom lens includes: a first lens group having a negative refractive power; a second lens group having a positive refractive power, including a cemented lens component L21 formed by combining a positive lens having a convex surface on the object side and a negative lens having a concave surface on an image side and a positive lens component L22 disposed on the image side with respect to the cemented lens component L21, spaced from the cemented lens component L21 by an air space and having a convex surface on the object side and disposed behind the first lens group with respect to an object side; and a third lens group having a positive refractive power and disposed behind the second lens group with respect to the object side.