Two studies were performed to investigate the effect of providing computer graphics enhancements to a perspective display on the observer's ability to estimate the azimuth and elevation separating two computer-generated images. The enhancements included the ability to rotate the perspective scene, the use of Lambertian shading, and the use of Lambertian shading with computer-generated shadows. The results indicated that the computer graphics enhancements of shadows and Lambertian shading did not aid subjects in judgments of azimuth or elevation. However, the ability to rotate the scene significantly improved judgments of elevation. Furthermore, this effect was most pronounced for larger elevation separations between images. The results also showed that the geometric field of view used to design the perspective display influenced the magnitude of azimuth errors. Implications of the results for the design of spatial displays are discussed.