The beam angle and the spill light are two related concepts in LED lighting. The spill light is the part of the light that does not fall within the beam angle, and it is usually indirect and dimmer. The beam angle is the angle between the two directions where the light intensity is half of the maximum on the plane of the beam axis.
The beam angle affects the size and brightness of the spot on the wall, as well as the amount and quality of the spill light. For example, if we use the same light source in different reflectors with different angles, we will get different results. The figure below shows how a spotlight with 10°, 24°, and 38° beam angles creates different spots on the wall with different power and different beam angles:
The following diagrams show the light distribution curves of the three beam angles:
We can see that the 10° spotlight has a small spot size and a high center light intensity, creating a strong contrast on the wall; the 38° spotlight has a large spot size and a low center light intensity, creating a soft and uniform spot on the wall; the 24° spotlight is somewhere in between.
This means that for LED lights with the same power, a larger beam angle will result in a lower center light intensity and a softer spill light, while a smaller beam angle will result in a higher center light intensity and a brighter spill light.
Remarks: Spill light and brightness of different beam angles
What beam angles are available in LED luminaires?
In practice, different beam angles have their own uses. Different types of LED lamps often have different lighting angles. For details, please refer to the following table:
| Category | Surface-led ceiling light | LED downlights | LED Spotlights | Outdoor façade lighting | UFO high bay led light | LED street light |
| Beam angle | 120°/140° | 60°/90°/120° | 15°/24°/36°/50°/60° | 5°/10°/30° | 60°/90°/120° | T1/ T2 /T3/T4/T5 |
Choosing the right beam angle for your LED lighting can make a big difference in how your space looks and feels. The beam angle is the angle at which the light spreads out from the source. A narrow beam angle means the light is more focused and less glare, but it also covers a smaller area. This can create a cozy and dramatic mood, but it can also make the space seem darker and contrasty. Spotlights are examples of lights with narrow beam angles.
A wide beam angle means the light is more diffuse and uniform, but it also may lack some character and atmosphere. This can create a bright and spacious feel, but it can also make the space seem bland and flat. Therefore, you should choose the beam angle that suits your space and purpose best.
| Beam angle | 10°/15° | 24°/36°45° | 60°/90°/120° |
| Feature | Because the central light intensity is prominent and the spot range is relatively small, it is generally suitable for accent lighting | Because the central light intensity is prominent and the spot range is relatively small, it is generally suitable for accent lighting | The light from the lamps hitting the ground will be more scattered Light and dark levels are not so obvious, suitable for providing basic lighting |
| Application | Exquisite ornaments such as vases, or decorations create a little gorgeous light | It can be used as a wall washer downlight or as partial lighting. The light rubs against the wall and washes down the wall. It has the feeling of raising the ceiling and reducing the sense of occlusion in the space. or dining table lighting, museum murals, living room paintings | Corridors, hotel halls, halls of shopping malls, office lighting, etc. |
Different beam angles for your LED lighting can create different effects and suit different purposes. The beam angle is how wide the light spreads from the source. Here are some examples of how to choose the right beam angle for different types of LED lighting:
