A method and system for improving the control of a holographic projection system in order to meet, or to attempt to meet, one or more targets or aims for a holographically reconstructed image that is produced by the holographic projection system. The target, or aim, may concern the luminance of part or all of the holographically reconstructed image.

There is disclosed herein a liquid crystal on silicon spatial light modulator, LCoS SLM, device arranged for in-plane switching. The LCoS SLM device comprises: a silicon backplane (1501); a transparent substrate (1581); a liquid crystal layer (1571); an electrode structure (1505, 1507) and a reflective component (1561, 1551). The liquid crystal layer (1571) is interposed between the silicon backplane (1501) and the transparent substrate (1581). The electrode structure (1505, 1507) is formed on the silicon backplane (1501) for generating an electric field in the liquid crystal layer (1571). The electric field is substantially parallel to the silicon backplane (1501). The reflective component (1551, 1561) is opposing the transparent substrate (1581).