A liquid crystal projector comprises first, second and third liquid crystal panels having corresponding light sources, namely a red light source, a green light source, and a blue light source, wherein the red light source. The light sources are preferably Semi-conductor generated light arrays. The projector further includes a dichroic prism for superimposing the red, green and blue image displays, and a projection lens for projecting a full-color image beam formed by the dichroic prism. In order to control the intensity of the light sources, a pulse modulating means is coupled to each of the Semi-conductor generated light arrays, the pulse modulating means being operable to independently switch each of the light sources between an on state and an off state at a selectable repetition rate. An embedded processor is coupled to the pulse modulating means, wherein the processor is operable to control the selectable repetition rates hereby the relative brightness of each of the red, green and blue light sources can be independently and selectively varied. The invention also discloses a method for providing a precise visual stimulus for any environment.