Choosing Lenses And Reflectors For LED Lights

There is no single parameter that can guarantee the optical performance of a given lens. We need to understand several parameters and the relationships between them, before arriving at a good lighting solution. And critical to this decision making process is an understanding of how LED lenses and reflectors can be combined for the best results.

- Deepshikha Shukla

The light from an LED’s primary optics is too broad for most applications, and lacks intensity over a distance. To alter the beam of light coming from the LED source, lighting fixtures require at least some type of secondary optics. There are four types of secondary LED optics—lenses, reflectors, TIR (total internal reflector) optics and holder kits. The secondary LED optics takes all the light within a given bulb or fixture, and magnifies the intensity towards the target, based on how the optics is designed. Secondary optics is not only made to collimate the light, but is sometimes also used to improve colour uniformity and light distribution within the targeted area. Choosing the appropriate optics or lens depends on the application. Reflectors and TIR optics are used for this purpose in many different applications, and both choices have advantages and disadvantages.

Secondary optics

Lenses are designed for use with single or multiple LEDs like LED modules or strips. Various properties of LED lenses enable the desired lighting effect and precise control over the beams of light. They come in various shapes and sizes—for example, round, square and hexagonal. The lens directs light from the centre of the source to the reflector, which then sends out a controlled beam in whichever direction it is designed to. Apart from this, additional surface treatments can be applied to shape light distribution.