Abstract: An ultra-wide-angle and large-aperture optical lens assembly with a high image quality is provided, including: a first lens, a second lens, a third lens, a fourth lens, and a filter which are arranged sequentially from an object side to an image side, and a diaphragm arranged between the second lens and the object side. The first lens has a positive focal power and includes a convex surface facing toward the image side. The second lens has a negative focal power and includes a concave surface facing toward the object side. The third lens has a positive focal power. The fourth lens has a negative focal power and has an object side surface and an image side surface both being aspheric surfaces, the object side surface of the fourth lens is arranged with an inflexion point. The lens assembly meets the relational expressions: 0.9<TTL/f1<2.5, 0.5<f/|f4|<1.6, and 0.4<D4/D1<0.9.

Abstract: An ultra-wide-angle and large-aperture optical lens assembly with a high image quality. The assembly comprises: a first lens (1) having a positive focal power and comprising a convex surface facing toward an image side; a second lens (2) having a negative focal power and comprising a concave surface facing an object side; a third lens (3) having a positive focal power; and a fourth lens (4) having a negative focal power, and surfaces facing the object side and the image side are aspheric surfaces. The lens assembly satisfies the following formulas: 0.9<TTL/f1<2.5; 0.5<f/f4|<1.6; and 0.4<D4/D1<0.9. The lens structure and lens layout smooth light passing through the lens assembly and correct an optical aberration accurately, and further correct an aberration of an off-axis visual field, resulting in low image distortion and high definition, ensuring a higher image quality while satisfying miniaturization.