Integrating Spheres for Reflectance Measurements

Properly measured reflectance can indicate an objects color and texture, and hint at the materials it’s made from. Specular reflection occurs on smooth surfaces like mirrors, and diffuse reflection occurs on rough or matte surfaces. Typical surfaces measured have both specular and diffuse components, though most of what we see in the world is a result of diffuse reflection from objects, so this is often the more key reflectance to measure. This application note discusses the use of integrating spheres for the purpose of reflectance measurements, and investigates the effectiveness of two Ocean Optics sphere models for measurement of flat and glossy paint samples and a medium-grit, commercial-grade sandpaper.