As we know , most LEDs have beam angle of 120° , but for street led lighting , 120° couldn't reach the best performance . So for LED street light , mostly have lens to control the beam angle , but accord to different streets and install position , one beam angle couldn't meet all different requirements .
In the initial stage of the LED industry ,CREE XRE XTE and COB LEDs were widely used for street led light products , but the COB LED have many disadvantages , especially the cooling .
The COB LED street light from china producers are still very popular in some markets , the design are very classic , and whole product very economic , with economic driver and quality LEDs , this kind of led street light is a good choice . The defective is the failure rate is higher and lumen effiency is low , and beam angle less choice .
As LED industry develops , SMD 3030 and 5050 is the main LEDs used for LED street lights , very stable quality , very good light performance , economic price .
Here are some lens light distribution curve of LEDIL :
The different lens are designed for different street lighting application , and even same beam angle lens , like we said T2 or T3 , lens from different producer come different results , and the designed curve may also have difference with the exact curve the street light lens produce .
And the lens designed for 3030 , normally couldn't used for 5050 , the LED position will also affect the light distribution curve performance , if the PCB wasn't designed preciously accord the lens , the curve will produced will have big difference .