Shifted sinusoidal illumination patterns are useful for appearance capture because they simultaneously separate local and non-local reflections and allow the recovery of surface geometry. Here we show that the same illumination patterns can be used to estimate the local surface reflectance (BRDF) as well, provided that an appropriate correction factor is applied. We derive a closed-form expression for this correction factor, validate it experimentally, and discuss its implications. 1 Preliminaries