Optical characteristics play an important role in the quality and visual aspect of lighting. The surface of the lens is the key factor. The optics designed for each application direct the light from the LED to the required direction and with the desired beam angle.
Here are a few tips for choosing the right optics:
1. Choose a lens that best suits the purpose
Different lighting objects require different characteristics. In the case of street lighting, one must pay special attention to the prevention of glare. The light must be distributed to the road surface at the right angle, so that there will be minimum glare in both dry and wet weather conditions.
2. Determine the importance of different characteristics
There are many factors which influence the choice of a lens. When choosing a lens for your solution, you are advised to determine which are the most important characteristics for the end purpose:
- Total shape of the light distribution curve
- Optical efficiency and energy efficiency
- Beam angle
- Ease of installation
- Aesthetic of the lens
3. Plan the target price level and lifetime for the chosen solution
The cheapest alternative is not always the best. For example, take two lenses with the same beam angles. The first product is 20 % cheaper, but it has lower efficiency, i.e. its power loss is higher. To reach the certain lumen/lux figure with the cheaper lens, you will need more power consumption for the solution – which shortens its lifetime – and eventually you will need to acquire more LEDs. Comparing the price, the lens is almost always cheaper than the LED.