A dispersing element for a rear projection screen assembly is sensitive to the polarization of the light passing through the element. In particular, the element disperses light having a first polarization differently from light having a second polarization orthogonal to the first polarization. The dispersing element may be aligned with a polarization axis neither parallel nor perpendicular to the polarization of the light passing through the element. The dispersing element may also be employed with a polarizer to remove unwanted light that propagates through the dispersing element. The dispersing element may also be rotatably mounted relative to a polarized light source so as to vary the angle between the polarization axis of the element and the polarization direction of the light.