Before buying a camera, always review its camera lens and make sure you choose the one that’s right for your business needs. Camera lens size decides the field of long–range surveillance and the angle of the security cameras observation. Generally, the length of fixed security camera lens is from 2.8mm to 12.0mm. Before buying a security camera, the customer should consider paying attention to the length of its lens. The larger the size of the lens, the more narrow and zoomed in the field of view is. The angle of lens section also relies on the image sensor chip. People have used popular sections are one – thirds.