Multi-cameras and in particular dual-cameras comprising a Wide camera comprising a Wide lens and a Wide image sensor, the Wide lens having a Wide effective focal length EFL.sub.W and a folded Tele camera comprising a Tele lens with a first optical axis, a Tele image sensor and an OPFE, wherein the Tele lens includes, from an object side to an image side, a first lens element group G1, a second lens element group G2 and a third lens element group G3, wherein at least two of the lens element groups are movable relative to the image sensor along the first optical axis to bring the Tele lens to two zoom states, wherein an effective focal length (EFL) of the Tele lens is changed from EFL.sub.T,min in one zoom state to EFL.sub.T,max in the other zoom state, wherein EFL.sub.Tmin>1.5×EFL.sub.W and wherein EFL.sub.Tmax>1.5×EFL.sub.Tmin.

Multi-cameras and in particular dual-cameras comprising a Wide camera comprising a Wide lens and a Wide image sensor, the Wide lens having a Wide effective focal length EFL.sub.W and a folded Tele camera comprising a Tele lens with a first optical axis, a Tele image sensor and an OPFE, wherein the Tele lens includes, from an object side to an image side, a first lens element group G1, a second lens element group G2 and a third lens element group G3, wherein at least two of the lens element groups are movable relative to the image sensor along the first optical axis to bring the Tele lens to two zoom states, wherein an effective focal length (EFL) of the Tele lens is changed from EFL.sub.T,min in one zoom state to EFL.sub.T,max in the other zoom state, wherein EFL.sub.Tmin>1.5×EFL.sub.W and wherein EFL.sub.Tmax>1.5×EFL.sub.Tmin.

The imaging lens consists of, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group, and a third lens group. During focusing, the second lens group moves. The first lens group includes a first positive lens disposed to be closest to the object side, a second positive lens disposed closer to the image side than the first positive lens, and an LA lens disposed closer to the image side than the second positive lens. Assuming that a partial dispersion ratio and an Abbe number thereof are respectively θgFA and vA, the LA lens satisfies 0.02<θgFA+0.001618×vA−0.6415<0.1. The imaging lens satisfies predetermined conditional expressions.

An optical lens assembly includes, in order from the object side to the image side: a first lens with positive refractive power, a stop, a second lens with negative refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, wherein a focal length of the optical lens assembly is f, the optical lens assembly has a maximum view angle (field of view) FOV, and following condition is satisfied: 0.16<f/FOV<1.27, so as to achieve the telephoto effect of the optical lens assembly.

An optical lens assembly includes, in order from the object side to the image side: a first lens with positive refractive power, a stop, a second lens with negative refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, wherein a focal length of the optical lens assembly is f, the optical lens assembly has a maximum view angle (field of view) FOV, and following condition is satisfied: 0.16<f/FOV<1.27, so as to achieve the telephoto effect of the optical lens assembly.

An imaging optical system includes six lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. Each of the six lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. At least one of the six lens elements is a freeform lens element, and at least one of the object-side surface and the image-side surface of the at least one freeform lens element is a freeform surface.

An imaging optical system includes three lens elements. The three lens elements, in order from an object side to an image side, are a first lens element having an object-side surface facing the object side and an image-side surface facing the image side, a second lens element having an object-side surface facing the object side and an image-side surface facing the image side, and a third lens element having an object-side surface facing the object side and an image-side surface facing the image side. The third lens element has positive refractive power, the imaging optical system has a total of three lens elements, and there are air gaps between paraxial regions of the first lens element, the second lens element and the third lens element.

A zoom optical system includes a first lens group, a position of which with respect to an imaging plane is adjustable, and including first and second lenses. The zoom optical system also includes a second lens group of which a position with respect to the imaging plane is adjustable and includes third to fifth lenses. The zoom optical system further includes a third lens group including a sixth lens. An object-side surface of the first lens is convex.

An imaging lens consisting of, in order from an object side to an image side: a first lens group that has a positive refractive power; a second lens group that has a positive refractive power; and a third lens group, wherein: during focusing, the second lens group moves along an optical axis, and the first lens group and the third lens group remain stationary with respect to an image plane, the second lens group includes a stop, an Lp1 lens, which is a positive lens, is disposed closest to the object side in the second lens group, an Lp2 lens, which is a positive lens, is disposed closest to the image side in the second lens group.

According to an embodiment of the disclosure, a lens assembly may include an image sensor, a first lens group disposed closest to an object side, the first lens group including multiple lenses and having negative power, a second lens group disposed to be moveable forward/backward along an optical axis direction, the second lens group having positive power, and a third lens group disposed to be moveable forward/backward along the optical axis direction, the third lens group including multiple lenses and having negative power, where the second or third lens group may move toward the object side so as to increase the focal length of the lens assembly, and the second lens group includes a lens having negative power and a lens having positive power and is disposed adjacent to the lens having negative power on the object side. In addition, various other embodiments may be possible.