Test targets, such as color charts, are often used for characterizing image capture systems. This paper describes a test target that uses three-dimensional sinusoids of varying orientation to analyze the illumination for a given scene. Specifically the magnitude of the contrast of the imaged sinusoids is used to estimate the angular orientation of the illuminant. A target consisting of sixteen sinusoids sampled every 11.25 degrees is shown to estimate the angular location of the illuminant to within 6.6 degrees in a laboratory setting. Furthermore this accuracy is achieved even with the introduction of a diffuser into the scene. This target is also used to differentiate two illuminants of differing chromaticity. In addition the target is used to differentiate the relative diffuseness of various locations on the bottom of a light booth. Finally the virtual target is also useful for understanding the illumination of 3D visualization software. The design and production of the target is described in more detail as are additional applications and use cases. The introduction of known three dimensional structure into test targets is a promising area for the design of targets for evaluation of image capture systems.