LED lens

An important component of LED lighting is the LED lens. As you’re probably aware from cameras, the lens is sometimes more important than the light source itself. With LED lighting, the principle is practically the same. The lens determines how the emitted light is distributed. In other words: it determines the optics of the light image. Several factors are crucial here: the curvature of the lens, its surface area and, of course, the thickness of the glass. The lens , in combination with the reflector and the emitted light, collectively determines the distribution and intensity of the light beam.

Different types of LED lenses

See the small protective dome above the diode? This is called the primary optics and helps protect and shape the output of small LED diodes. The light from the LED's primary optics is still too wide for most applications and too weak to lighten only certain surfaces. Therefore, most LED lamps use secondary optics (lenses, reflectors, TIR optics, etc.) to capture all the light from the LED and increase its intensity. The most common LED lens is the convex lens placed around the LED. However, as technology advances, other types of lenses have also become more common. For example, there are square lenses, 'high dome' lenses, 'medium dome' lenses and flat lenses. Each with its own light distribution and mounting over the LED diode.

Optical features of different LED lenses

If you are looking for a specific light image in your LED lighting, it is important to know what kind of lens your light uses. To make this clear, we have made a table with the differences.

Convex lens

The more domed lenses used with LEDs often ensure a uniformly distributed light beam. If the curvature of the lens lies flat against the LED chip, you can expect a fairly uniform light pattern. Is the curvature of the lens high and long? Then you will see that the light beam is more focused on a single specific point. This can be described as a focused light image. The interior shape of the lens also affects the light emitted. For example, a square interior (low, square lens) produces a different light distribution to that of a convex interior. An example of a light that uses a square interior combined with a convex lens is the Fish-eye-equipped optimus serie.

Flat lens

In the same table, you can also see that there are two models with a flat lens. This flat lens can be found both on the inside and on the outside. Because of this, you can see that the light distribution is hardly affected by the lens present. So you can see this as a protection of the LED diode rather than an actual optically changing part.

Is one type of LED lens better than another?

The answer to this is simple: No! A light is made up of several components which, together, determine the light image. Although the LED lens is of great importance to this light image, it must always be considered in combination with a reflector or the cover glass. With an LED work light, for example, you can use different types of lenses for different applications. The same applies to LED rear lights, where the lens , in combination with a distinctive colour, must emit light. For this reason, an LED lens is neither ‘good’, ‘bad’ nor ‘better’. Seek advice from specialists if you’d like to add LED lighting to your machine.

The materials in LED lenses are different

As lenses, as mentioned earlier, can serve various purposes, different materials are used. One of the most common materials is PMMA. By heating this material and using a sturdy mould, this clear, reflective material can easily be moulded into the desired shape. This offers a certain advantage when manufacturing LED lenses. The material is also highly resistant to heat. If you wish to fit a specific lens to a powerful light source that emits heat, it is important that this lens does not warp over time and consequently lose the desired light image. Other materials you may come across include polycarbonate and glass. However, these are quite expensive to incorporate into your lighting.