Patent ID: 8743477

Claim:
An optical photographing lens system comprising, in order from an object side to an image side: a first lens element with negative refractive power having a convex object-side surface and a concave image-side surface; a second lens element having positive refractive power; a third lens element having refractive power; a fourth lens element having refractive power, wherein at least one of an object-side surface and an image-side surface of the fourth lens element is aspheric; a fifth lens element with positive refractive power having a convex image-side surface, wherein an object-side surface and the image-side surface of the fifth lens element are aspheric; and a sixth lens element having negative refractive power, wherein an image-side surface changes from concave at a paraxial region to convex at a peripheral region, and an object-side surface and the image-side surface of the sixth lens element are aspheric; wherein a focal length of the optical photographing lens system is f, a focal length of the second lens element is f2, a curvature radius of the object-side surface of the fifth lens element is R9, and a curvature radius of the image-side surface of the fifth lens element is R10, the following relationships are satisfied: 0 <f/f 2<1.0; and | R 10 /R 9|<0.9.