Lens assembly

A lens assembly, comprising:

• a first lens, a second lens and a third lens from an object side of the lens assembly to an image side of the lens assembly, in turn, wherein:
• the first lens is of a positive refractive power, and an object side of the first lens is of a convexity;
• the second lens is of a negative refractive power;
• and
• the third lens is of a positive refractive power, and an image side of the third lens is of a concavity and has one inflection point,
• wherein the lens assembly meets the following formulas:
• tan(HFOV)>0.74;
• TTL/ImgH<1.7;
• 0.6<f1/f<0.8;
• and
• −1.3<f1/f2<−0.8,
• wherein HFOV represents a horizontal field of view and equals to half of a field angle of the lens assembly,
• TTL represents a total track length of the lens assembly,
• ImgH represents half diameter of an effective pixel region of the lens assembly at an imaging plane,
• f1 represents a focal length of the first lens,
• f2 represents a focal length of the second lens, and
• f represents an effective focal length of the lens assembly.