Optical lens assembly for image taking

An optical lens assembly for image taking comprising, in order from an object side to an image side:

• a first lens element with positive refractive power comprising a convex object-side surface at a paraxial region and an image-side surface;
• a second lens element with negative refractive power comprising a concave object-side surface at a paraxial region and an image-side surface;
• a third lens element with refractive power comprising a concave object-side surface at a paraxial region and a convex image-side surface at a paraxial region;
• and
• a plastic fourth lens element with negative refractive power comprising a concave object-side surface at a paraxial region and a concave image-side surface at a paraxial region, wherein both of the object-side surface and the image-side surface are aspheric, and the image-side surface is convex at a peripheral region;
• wherein the optical lens assembly for image taking has a total of four lens elements with refractive power, a magnitude of a curvature radius of the object-side surface of the fourth lens element is greater than a magnitude of a curvature radius of the image-side surface of the second lens element, the optical lens assembly for image taking further comprises a stop, T23 is an axial distance between the second lens element and the third lens element, CT3 is a central thickness of the third lens element, R1 is a curvature radius of the object-side surface of the first lens element, R2 is a curvature radius of the image-side surface of the first lens element, Dsr4 is an axial distance between the stop and the image-side surface of the second lens element, Dr1r4 is an axial distance between the object-side surface of the first lens element and the image-side surface of the second lens element SAG32 is a distance in parallel with an optical axis from a maximum effective diameter position on the image-side surface of the third lens element to an on-axis vertex on the image-side surface of the third lens element, and the optical lens assembly for image taking satisfies the following conditions:
• 1.50≦T23/CT3<2.05;
• −0.33<R1/R2<0.50;
• 0.30<Dsr4/Dr1r4<0.90;
• and
• 1.2<|SAG32|/CT3<1.5.