Asymmetric and symmetric beam angles are two terms that describe the shape and direction of the light emitted by a light source, such as a LED fixture. The beam angle is the angle between the two directions for which the intensity of the light is 50% of the maximum intensity. Asymmetric beam angles have different values along different axes, while symmetric beam angles have the same value along all axes. Asymmetric and symmetric beam angles have different applications and benefits for lighting design.
We will compare asymmetric and symmetric beam angles in terms of their efficiency, spectrum, intensity.
- Efficiency: Usually, asymmetric beam angles have a higher lumen per watt and PPE than symmetric beam angles. This means that they produce more visible light and more PAR per watt than symmetric beam angles. This is because asymmetric beam angles can direct the light toward a specific direction or area, reducing light pollution and unwanted glare. Symmetric beam angles emit light in all directions equally, wasting light and creating intentional or unintentional glare.
- Intensity: Intensity measures how much light a fixture delivers to the target area. The intensity of a fixture depends on its light output and coverage area. Light output is a measure of the total amount of light that a fixture emits, expressed in lumens or micromoles per second (µmol/s). Coverage area is a measure of the size of the area that a fixture can illuminate, expressed in square feet or meters. Asymmetric beam angles have a lower light output but a larger coverage area than symmetric beam angles. This means that they provide less light but more uniformity to the target area. Asymmetric beam angles can also deliver more penetrating light to the lower parts of plants or objects, as they have less reflection and scattering by dust, moisture, and pollutants in the atmosphere. Symmetric beam angles have a higher light output but a smaller coverage area than asymmetric beam angles. This means that they provide more light but less uniformity to the target area. Symmetric beam angles can also create hot spots and dark spots in the canopy or surface, as they have more reflection and scattering by dust, moisture, and pollutants in the atmosphere.
The difference between asymmetric and symmetric beam angles on LED sports light is that asymmetric beam angles have different values along different axes, while symmetric beam angles have the same value along all axes. Asymmetric beam angles can direct the light towards a specific direction or area, reducing light pollution and unwanted glare. Symmetric beam angles emit light in all directions equally, wasting light and creating intentional or unintentional glare. Asymmetric beam angles are more efficient, flexible, uniform, cool, durable, long-lasting, and low-maintenance than symmetric beam angles. Symmetric beam angles are more powerful, bright, warm, fragile, short-lived, and high-maintenance than symmetric beam angles. The choice between asymmetric and symmetric beam angles depends on the purpose, preference, and budget of the user.
