led beam angle
The relationship between the angle and the light intensity is analyzed.First the lens angle is determined that angle of led beam. simply add the corresponding angle lens in echo led. then we can lock led beam angle . there are has a lot kind of lens from different angle. such as: 8°、15°、25°、45°、60°、90°、120°，it can be classified into three categories to help identify see led beam angle more clearly base on beam angle.
narrow beam: ＜20°；
middle beam: 20°~40°；
weight beam: ＞40°。