The beam angle of an LED light indicates the angle at which the light beam opens and therefore defines the area that can be lit depending on the distance to the light source. It must be taken into consideration that LEDs are much more focal than, for example, halogens and therefore we must pay special attention to this aspect.
This is one of the most important aspects to be aware of when planning the lighting of a room.
Which beam angle should I choose?
Depending on the intended purpose, we will be looking for a different aperture angles. Lights with a smaller beam angles are usually used as accent lighting, to highlight decorative elements or, in the case of a store, the different products. On the other hand, luminaires with a wider angle, usually 90º and wider, are used for general lighting.
To choose the angle we must take into account the height and surface to be illuminated. If the height is high and we have a very wide angle, we will lose light intensity compared to a more focused light, but the light will be better distributed. On the contrary, for general lighting of room with low height, if we use a narrow beam angle, shadows can be created because the lit areas will be very defined, similar to the effect of using a flashlight.
How can I calculate the that will be lit based on the beam angle?
In this section we are going to get a little more technical and we will show you, with a small formula, how to perform the calculations we have used to make the previous graphs.
To know the width of the lit area, given a beam width and a height, we will apply the formula shown below:
Where:
- a is the width of the space to be illuminated.
- α is the beam angle of our light source.
- b is the height at which the light source is located.
How can I calculate the aperture angle I need?
If we want to calculate the beam angle we need to illuminate an area from a certain height we can use the following formula:
Where:
- α is the angle we want to know.
- a is the width of the space to be lit.
- b is the height at which the light source is located.
Bear in mind that these calculations, although correct, are only orientative. When choosing a lamp or bulb we must take into account other aspects such as the brightness it provides or the distribution of the light spots.