A C-plate compensator is disclosed for compensating the residual A-plate and C-plate retardance of a reflective liquid crystal on silicon (LCoS) display or a transmissive liquid crystal (LC) display in a projection display system. The C-plate incorporates a form-birefringent coating, whose retardance magnitude can be adjusted by tilting with respect to the display panel (X-Y) plane. The tilted plate is rotated about the Z-axis by a prescribed amount from the slow axis of the display panel. Criteria are described for choosing the tilt and rotation angles such that the contrast of the display system produced by the compensated panel is optimized.