Abstract: This invention relates to optical systems for holographic projectors. We describe a holographic image projection system, the system including: a spatial light modulator (SLM) for displaying a hologram; first optics to provide an input beam to said SLM; second optics to process an output beam from said SLM to provide a displayed image; and a hologram processor to receive image data for display and to output data to said SLM to display a hologram to provide said displayed image; and wherein at least one lens of said first optics or said second optics is encoded in said hologram.