A wide-angle lens (100) includes a front group (110), an aperture (80), and a rear group (120). The front group (110) includes a first lens (10) and a second lens (20) arranged from a side (La) closest to an object to an image side (Lb). In such a wide-angle lens, to suppress an occurrence of a ghost caused by multiple reflection between a lens surface (102) of the first lens (10) on the image side (Lb) and a lens surface (21) of the second lens (20) on the object side (La), the sag amount Sag21 (mm) and the diameter D21 (mm) of the lens surface (21) satisfy the following conditional expression: 0<|Sag21/(D21/2)|<0.125.

An imaging lens consists of a front group and a rear group in order from the object side to the image side. The front group includes, as lenses, in order from the object side to the image side, only a positive meniscus lens having a surface convex toward the object side, a first cemented lens having a negative power as a whole, and a second cemented lens having a positive power as a whole. In the first cemented lens, a positive lens and a negative lens are cemented in order from the object side, with a surface convex toward the object side and a surface concave toward the image side. The rear group includes a negative most image side lens having a surface concave toward the object side at a position closest to the image side.

An imaging lens consists of a front group and a rear group in order from the object side to the image side. The front group includes, as lenses, in order from the object side to the image side, only a positive meniscus lens having a surface convex toward the object side, a first cemented lens having a negative power as a whole, and a second cemented lens having a positive power as a whole. In the first cemented lens, a positive lens and a negative lens are cemented in order from the object side, with a surface convex toward the object side and a surface concave toward the image side. The rear group includes a negative most image side lens having a surface concave toward the object side at a position closest to the image side.

An optical system includes, in order from an object side to an image side, a front unit having a positive refractive power and including one or more lens units configured to move during focusing, and a negative lens unit having a negative refractive power. The one or more lens units included in the front unit moves to the object side during focusing from infinity to a short distance so as to widen a distance between the front unit and the negative lens unit. The front unit includes a first subunit having a negative refractive power and including a lens disposed on the object side of a first positive lens that is one of positive lenses included in the optical system, which is the closest to an object. A predetermined condition is satisfied.

An optical system includes, in order from an object side to an image side, a front unit having a positive refractive power and including one or more lens units configured to move during focusing, and a negative lens unit having a negative refractive power. The one or more lens units included in the front unit moves to the object side during focusing from infinity to a short distance so as to widen a distance between the front unit and the negative lens unit. The front unit includes a first subunit having a negative refractive power and including a lens disposed on the object side of a first positive lens that is one of positive lenses included in the optical system, which is the closest to an object. A predetermined condition is satisfied.

An optical system (OL) formed from a preceding lens group (GA) having a negative refractive power, and a succeeding lens group (GB) having a positive refractive power, the lens groups being arranged in order from the object side along the optical axis. The succeeding lens group (GB) has: a focusing group (GF) having a positive refractive power, the focusing group (GF) being positioned furthest toward the object side of the succeeding lens group (GB); and an image-side group (GC) positioned further toward the image side than the focusing group (GF). During focusing from an infinitely distant object to a short-distance object, the focusing group (GF) moves toward the image side along the optical axis and satisfies the following conditional expression.

0.78<fB/fC<1.00

In this conditional expression,

fB is the focal distance of the succeeding lens group GB, and

fC is the focal distance of the image-side group GC.

An optical imaging system includes five lens elements, the five lens elements being, in order from an object side to an image side: a first lens element having positive refractive power; a second lens element having negative refractive power; a third lens element having positive refractive power; a fourth lens element having positive refractive power; and a fifth lens element having negative refractive power.

An optical imaging system includes five lens elements, the five lens elements being, in order from an object side to an image side: a first lens element having positive refractive power; a second lens element having negative refractive power; a third lens element having positive refractive power; a fourth lens element having positive refractive power; and a fifth lens element having negative refractive power.

An optical imaging lens assembly includes, in order from an object side to an image side: a first, a second, a third, a fourth, a fifth and a sixth lens elements. The first lens element has negative refractive power. The second lens element has an object-side surface being concave in a paraxial region thereof. The third lens element has an object-side surface being convex in a paraxial region thereof. The fifth lens element with negative refractive power has an object-side surface being concave and an image-side surface being convex in a paraxial region thereof. The sixth lens element has an image-side surface being concave in a paraxial region thereof. At least one of an object-side surface and the image-side surface of the sixth lens element has at least one critical point in an off-axis region thereof, wherein both the surfaces of the sixth lens element are aspheric.

An optical image capturing system includes, along the optical axis in order from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. At least one lens among the first to the sixth lenses has positive refractive force. The seventh lens has negative refractive force. Both an object-side surface and an image-side surface of the seventh lens are aspheric surfaces. At least one surface of the seventh lens has at least an inflection point thereon. The lenses in the optical image capturing system which have refractive power include the first to the seventh lenses. The optical image capturing system can increase aperture value and improve the imaging quality for use in compact cameras.