Abstract: Many 3D displays show 3D images to viewers wearing special eyeglasses, while showing a double image to viewers without eyeglasses (13e). We demonstrate a method (15a-15h) that provides those with eyeglasses a 3D experience while viewers without eyeglasses see a 2D image without artifacts (FIG. 1, image 1b). In addition to separate Left (“L”) and Right (“R”) images in each frame, we add a third image (“N”), invisible to those with glasses. In the combined view seen by those without glasses, this cancels the Right image, leaving only the Left. If the Left and Right images are of equal brightness, this approach results in low contrast to viewers without glasses. Allowing differential brightness between the Left and Right images improves 2D contrast. We determine that viewers with glasses maintain a strong 3D experience, even when one eye is significantly darker than the other.