Part 4. How to choose the right Beam Angles?
The beam angle generally applies to fixtures, but can also be used for reflector-type light sources, although this standard doesn't explicitly specify when to use 10% or 50%.
In practical applications, the CIE (International Commission on Illumination) recommends a beam angle as the angle between the radii where the light intensity is 50% of the maximum. Meanwhile, the IES (Illuminating Engineering Society of North America) suggests the beam angle as the angle between the radii where the light intensity is 10% of the maximum. For non-symmetric fixtures, such as within a section where C=0° (horizontal) and γ=0° (vertical), the angle of the beam with 10% of peak intensity might differ, meaning the beam angles in the horizontal and vertical directions could be different.
Generally, the beam angle for spotlights ranges from 10° to 60°, while for ceiling lights, it's around 140°.
The beam angle of a fixture reflects on the illuminated wall/floor as the size and brightness of the light spot. A larger beam angle corresponds to a smaller central light intensity and a larger light spot. Conversely, a smaller beam angle results in higher ambient light intensity and poorer scattering effects.
Narrow Beam Angle（10°-20°）
A 20° beam angle is classified as narrow, characterized by strong central light intensity and focused illumination, making it suitable for accent lighting. Delicate ornaments in museums often opt for a 15° beam angle to highlight them, and similarly, decorative items in homes can also benefit from a 15° beam angle, drawing attention as visual focal points.
Wide Beam Angle (24°-45°)
Using spot light wall washer can create a graduated halo effect, adding depth to the lighting. Additionally, if there are paintings or decorative artworks on the wall, the light can illuminate them, enhancing the texture, quality, and colors of the artwork. This approach also elevates the contrast and lighting layers within the space, enhancing the overall visual appeal.
A 24° beam angle provides a broader coverage compared to 15°, with bright illumination suitable for accent and wall washing. It accentuates light layers and contrasts within a space, and when used for wall washing, it can create distinct, hill-like light spots.
With a 36° beam angle, the resulting light spot on the illuminated surface is relatively soft, creating a uniform, large arc of light. It's ideal for illuminating wall decorations like paintings, enhancing their texture and color. It can also serve as lighting for corridors and hallways without overly concentrated light.
After testing in the lighting optics laboratory, it was found that within the medium beam angle range, a 30° beam angle provides a more balanced illumination area, making it particularly suitable for everyday use in home settings. Hence, spotlights with a 30° beam angle have been specially designed and introduced.
The light from a 30° beam angle spotlight is gentle, catering to both accent and wall washing lighting needs. Its versatility makes it convenient for practical applications, eliminating the need to decide between different beam angles, as one with a 30° angle can serve both accent and wall washing purposes.
Flood Beam Angle(50°-60°)
Compared to a wide beam angle, the extra wide beam angle (50°-60°) spreads light even further, resulting in more diffuse illumination on the ground. This makes it well-suited for providing ambient lighting, as the light is dispersed across a wider area. However, the contrast between light and shadow is relatively less pronounced, leading to fewer discernible light and dark areas.
Part 6. Conclusion
For beam angles less than 20°, they are considered narrow beams, which are typically suitable for accent lighting, such as highlighting decorative items or art pieces.
Beam angles ranging from 20° to 40° are classified as medium beams. They can be used for wall washing or localized lighting, creating attractive highlights on the wall or directing attention to specific areas. Beam angles greater than 40° are wide beams, dispersing light more widely and are suitable for providing ambient lighting.
Among these, the 24° beam angle is often referred to as the universal beam angle. It produces a soft and aesthetically pleasing light distribution, making it suitable for wall washing, accent lighting, or general illumination.
If you're unsure about which beam angle to choose, opting for a 24° beam angle light can help reduce the likelihood of errors.
