Beam Angle and Its Impact on Red Light Therapy ResultsLast Updated:
Beam angle determines the level of intensity at which the beam of red light from each bulb in a panel connects with your skin. Red light therapy devices on the market today are available in a range of beam angles.
Before discussing the treatment implications of beam angle variations, it is helpful to understand the language of the LED lighting world.
If you wish to proceed directly to the “nuts and bolts” of LED beam angles, just scroll down to the next section and refer back to the “Technical Terms and Definitions” section as needed! This section is intended only to help you understand the technical terminology surrounding red light therapy and LED lighting.
Table of Contents
Technical Terms and Definitions
Inverse Square Law
Minimum Usage Distance
Light Density (Intensity)
How Does Beam Angle Impact the Way Red Light Waves Connect With Your Body?
Red light therapy utilizes refractive lenses in its bulbs, providing maximum absorption of red light wavelengths into your body.
Red light density varies in irradiance level based upon the beam angle of your device.
Wider beam angles diversify (spread apart) red light waves more quickly due to the inverse square law. As beams of light diversify, they lose their intensity and intrinsic healing powers with increased distance between you and the device.
Narrower beams offer less bodily coverage since they are straighter and cover less surface area from a distance, but they do offer more concentrated intensity from longer distances, improving benefits.
It could be more beneficial for light to reach your body more directly in the form of perpendicular (more narrowly angled) beams of light.
Which is better? Greater bodily coverage with wider angled beams, or more targeted, straight light waves administered via lower angled beams? Light scatter and reflection decrease with a minimized distance, but light absorption is maximized at a greater distance. Therein lies the conundrum!
The verdict is not yet in. But, each option offers its own unique treatment solutions.
The Most Common Beam Angles for Red Light Therapy Device Bulbs and Their Attributes
A natural level for a general-purpose LED bulb angle is 120 degrees; however, via the use of lenses and reflectors, light beams can be focused to customized levels for red light therapy.
The most common red light therapy LED beam angles are 90, 60, 30, and 10 degrees. When selecting a red light therapy device, pay close attention to the recommended minimal usage distance. The closer you will be to the device during therapy, the less important the beam angle is.
The differing attributes of red light therapy derived from devices with various refracting lens beam angles:
This is a very specialized and straight projection of light. While you experience the maximum level of red light absorption, it might be too highly concentrated at the minimum usage distance. The beams of light may not yet be dispersed enough to provide thorough coverage.
To date, there is little evidence to support the supremacy of one lens beam angle over another. Consider your unique health and fitness goals when selecting a red light therapy device, bringing beam angle into the equation as you see fit.
Additional Resource Material
Not much research or reading material is currently available on optimal lens beam angles for red light therapy. Unless scientific studies begin to address the topic, it will remain up to you to determine how beam angle impacts your unique treatment needs.
For now, here is some additional reference material to help you further understand the science behind LED lenses and light beam angles.
- sciencedots.com - Inverse Square Law (opens in a new tab)
- sciencedirect.com - Beam Angle (opens in a new tab)
- sciencelearn.org.nz - Reflection of Light (opens in a new tab)
- sciencedirect.com - Light Irradiance (opens in a new tab)
- gsu.edu - Refraction of Light (opens in a new tab)
- physicsforums.com - What Is the Density of Light? (opens in a new tab)
- Role of EMF in red light therapy
Until a better understanding of beam angle impact upon the success of red light therapy success is gained, it is best to focus on other parameters when selecting a device. Pay more attention to the light intensity at the recommended minimum usage distance.
Personal objectives as to beam angle should be considered when selecting a red light therapy device. Until more concrete scientific evidence is available, however, the science behind the total therapeutic energy provided is a more reliable metric than beam angle.