Patent attributes
A photographing optical system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element with positive refractive power has a convex object-side surface and a concave image-side surface. The third lens element with negative refractive power has a concave image-side surface. The fourth lens element has positive refractive power. The fifth lens element with negative refractive power has a concave image-side surface, wherein the image-side surface of the fifth lens element comprises at least one convex shape thereon, and two surfaces of the fifth lens element are aspheric.