Abstract: A zoom lens system includes in order from an object side to an image side a first lens unit having a positive refracting power; a second lens unit having a negative refracting power; a third lens unit having a positive refracting power; and a fourth lens unit having a positive refracting power. At the time of zooming from a wide angle end to a telephoto end, each of distances between the first lens unit and the second lens unit, between the second lens unit and the third lens unit, and between the third lens unit and the fourth lens unit is changed, and the first lens unit is moved. The first lens unit includes a lens component having positive refracting power, a total number of lens components included in the first lens unit is one, and the third lens unit includes five lens elements.

Abstract: A zoom lens includes a negative first lens unit G1 and a positive second lens unit G2. The second lens unit G2 includes first and second cemented lens components that are arranged adjacent to each other. The first and second cemented lens components are each made up of a plurality of lens elements having different refractive indices and different Abbe constants. The image side surface of the first cemented lens component and the object side surface of the second cemented lens component are both concave surfaces.

Abstract: A zoom lens system includes in order from an object side to an image side, a first lens unit G1 having a positive refracting power, a second lens unit G2 having a negative refracting power, a third lens unit G3 having a positive refracting power, and a fourth lens unit G4 having a positive refracting power. At the time of zooming from a wide angle end to a telephoto end, distances between the lens units change. The third lens unit includes a first cemented lens component having a concave image-side surface on the image side, and a second cemented lens component having a concave object-side surface on the object side, which is disposed immediately after the image side of the first cemented lens component. The first cemented lens component includes a positive lens, and a negative lens having a concave image-side surface which is disposed on the image side of the positive lens.

Abstract: A zoom lens includes a negative first lens unit G1 and a positive second lens unit G2. The second lens unit G2 includes first and second cemented lens components that are arranged adjacent to each other. The first and second cemented lens components are each made up of a plurality of lens elements having different refractive indices and different Abbe constants. The image side surface of the first cemented lens component and the object side surface of the second cemented lens component are both concave surfaces.

Abstract: A zoom lens system includes in order from an object side to an image side, a first lens unit G1 having a positive refracting power, a second lens unit G2 having a negative refracting power, a third lens unit G3 having a positive refracting power, and a fourth lens unit G4 having a positive refracting power. At the time of zooming from a wide angle end to a telephoto end, distances between the lens units change. The third lens unit includes a first cemented lens component having a concave image-side surface on the image side, and a second cemented lens component having a concave object-side surface on the object side, which is disposed immediately after the image side of the first cemented lens component. The first cemented lens component includes a positive lens, and a negative lens having a concave image-side surface which is disposed on the image side of the positive lens.