Optical system for photographing, image capture unit and electronic device

Abstract

An optical system for photographing, comprising six lens elements (E1, E2, E3, E4, E5, and E6), wherein the six lens elements (E1, E2, E3, E4, E5, and E6) are, in order from an object side to an image side along an optical path, a first lens element (E1), a second lens element (E2), a third lens element (E3), a fourth lens element (E4), a fifth lens element (E5), and a sixth lens element (E6), and each of the six lens elements (E1, E2, E3, E4, E5, and E6) has an object-side surface facing the object side and an image-side surface facing the image side; wherein the first lens element (E1) has a negative refractive power, the object-side surface of the first lens element (E1) is concave in a paraxial region thereof, the object-side surface of the first lens element (E1) has at least one inflection point (P), the third lens element (E3) has a negative refractive power, the object-side surface of the third lens element (E3) is concave in a paraxial region thereof, the fifth lens element (E5) has a positive refractive power, the object-side surface of the sixth lens element (E6) is convex in a paraxial region thereof and the image-side surface of the sixth lens element (E6) is concave in a paraxial region thereof; wherein the optical system for photographing further comprises an aperture stop (ST), a radius of curvature of the image-side surface of the fourth lens element (E4) is R8, and a radius of curvature of the object-side surface of the fifth lens element (E5) is R9; and wherein, with a wavelength of the helium d-line as a reference wavelength for the photographing optical system, a focal length of the photographing optical system is fd, a focal length of the third lens element (E3) is f3d, a focal length of the fifth lens element (E5) is f5d, and an axial distance between the aperture stop (ST) and an image surface (IMG) is SLd, and the following conditions are satisfied: 1.00 < | R8 / R9 | < 5.00 ; 0.20 < | f3d / f5d | < 7.00 ; and 2.80 < SLd / fd < 4.50.

Images