NeoPixels and other addressable LED strips are so much fun to use, and there are so many possibilities and ways to make beautiful things. The pixels are gorgeous on their own, but when they're diffused through or reflected off other objects, they can become pure magic.

Adafruit's engineers and artists have pooled some of our experience and knowledge about diffusion materials and techniques. We've tested some common materials, as well as specialty materials and interesting stuff we've found and love in hopes that you'll be inspired and accelerated on your journey toward making beautiful things with electronics.

What Is Diffusion?

Diffusion is the scattering of light by transmission or reflection. When light passes through a diffusing material, such as a frosted glass or a piece of plastic, the material scatters the light in many different directions, which reduces the intensity and sharpness of the light. This happens because the diffusing material contains microscopic irregularities, such as tiny air pockets or particles, that cause the light to refract and reflect in different directions. As a result, the light becomes more evenly distributed and softer, creating a more diffuse and pleasing effect. The amount of diffusion depends on the degree of irregularities in the diffusing material, as well as its thickness and distance from the light source.

Diffusion and NeoPixels

NeoPixel LEDs are a popular choice for creating dynamic and colorful lighting displays, but sometimes their brightness and sharpness can be too intense for certain projects. This is where diffusion comes in. Diffusing NeoPixel LEDs involves softening the light emitted from the individual LEDs to create a more even and diffuse glow. Diffusion can help to reduce the harshness of the light, make it easier on the eyes, and create a more aesthetically pleasing effect. This tutorial will explore various methods for diffusing NeoPixel LEDs and how to achieve the desired level of diffusion for your specific project.

LED Test Setup

I'm running a rainbow animation on 6 different types of LED strips. From left to right: 

For diffusion, the material matters a lot, but the distance at which you place the diffusing material matters even more. I've taken some images and video of a lot of different materials, first with the material flush against the strips, and then hovering about 1" away. In the video clips I slowly pull the material further from the strips until it's about 8 inches from the table.

All photos and video were taken on an iPhone 12pro with no editing or color correction.