fresnel lens a holographic lens or in the alternative another arrangement of one or more lenses and or other optical elements which will guide light in the direction of a viewing area in the illustrated embodiment collimator 18 causes light to travel through the elements of second light modulator 20 in a direction which is generally normal to screen 23 as light incident from collimator 18 travels through second light modulator 20 it is further modulated the light then passes to a diffuser 22 which scatters the outgoing light through a range of directions so that a viewer located on an opposite side of diffuser 22 from first light modulator 16 can see light originating from the whole area of screen 23 in general diffuser 22 may scatter light to a different angular extent in the horizontal and vertical planes diffuser 22 should be selected so that light modulated by second light modulator 20 is scattered through a range of angles such that the maximum scatter angle is at least equal to the angle subtended by screen 23 when viewed from a desired viewing location rear projection screen 23 may differ in area from first light modulator 16 for example rear projection screen 23 may be larger in area than first light modulator 16 where this is the case optical system 17 expands the beam of light modulated by first light modulator 16 to illuminate a larger corresponding area.