A new device for measuring the spatial reflectance distributions of surfaces is introduced, along with a new mathematical model of anisotropic reflectance. The reflectance model is both simple and accurate, permitting very efficient reflectance data reduction and reproduction. The validity of the model is substantiated with comparisons to complete measurements of surface reflectance functions gathered with a new reflectometry device. This device uses imaging technology to capture the entire hemisphere of reflected directions instantly, which greatly accelerates the reflectance data gathering process and makes it possible to measure dozens of surfaces in the time that it used to take to do one. Example measurements and simulations are shown, and a table of fitted parameters for several surfaces is presented.