Abstract: An optical lens, in order from an object side to an image-forming side, includes: a first lens having positive refractive power, a second lens having positive refractive power, a third lens having positive refractive power, and a fourth lens. The distance from an outer edge of the image-side surface of the fourth lens to an optical axis of the optical lens is H. The image-side surface of the fourth lens has an inflection point, and the distance from the inflection point to the optical axis is h. The image-side surface of the fourth lens and the optical axis intersect at an intersection point. The distance between a projected position of the inflection point on the optical axis and the intersection point is d0. The optical lens satisfies at least one of the following conditions: 0.6?h/H, h/H?0.95, 3.75?H/d0 and H/d0?30.

Abstract: A zoom lens primarily includes, in order from an object side to an image-forming side, a first lens group having negative refractive power; a second lens group having positive refractive power and at least consisting of a first lens and a second lens; and a third lens group having positive refractive power. The refractive index of the first lens (Nd21), the refractive index of the second lens (Nd22), the total length of the first lens group, the second lens group, and the third lens group (TTL), and the shortest focal length of the zoom lens (fw) satisfy the following conditions: Nd21?Nd22>0.1 and TTL/fw?1.3.

Abstract: A zoom lens primarily includes, in order from an object side to an image-forming side, a first lens group having negative refractive power; a second lens group having positive refractive power and at least consisting of a first lens and a second lens; and a third lens group having positive refractive power. The refractive index of the first lens (Nd21), the refractive index of the second lens (Nd22), the total length of the first lens group, the second lens group, and the third lens group (TTL), and the shortest focal length of the zoom lens (fw) satisfy the following conditions: Nd21?Nd22>0.1 and TTL/fw?1.3.