The ultimate goal of any auto-stereoscopic display is to reproduce exact light fields of 3D scenes on the display’s surface. However, most existing displays can only reproduce inexact light fields. Filling the gap between them has been a major target of research. In this work, we present a light field modulator consisting of a LC (liquid crystal) panel, a light diffuser, and a pair of lenticular sheets. The modulator will modify the intensity of light passing through it. When combined with a color filter, the modulator can also modify the color tone. Since the modification is dependent on the light’s direction, the modulator can be tuned to improve the light field from being inexact to being nearly exact. To further investigate the modulator’s capability, we put it in front of a multi-layer display. The light fields reproduced by a multi-layer display are only approximate especially when the display is tailored to cover a wide viewing zone. We observe that the modulator can mitigate the occurrence of artifacts in the outputted light fields. We also observe that monochromatic fields can be converted into color fields using the modulator. © 2016, Society for Imaging Science and Technology (IS&T).