A parallax barrier comprises evenly spaced groups of slits. Each group comprises two or more slits which are evenly spaced and the groups are spaced with a period which is greater than the product of the number of slits in each group and the slit period in each group. Such a barrier may be used with a spatial light modulator having columns of pixels whose structure cooperates with the barrier structure to provide a wider angle between views in a multiple view display, such as an autostereoscopic 3D display or a display providing two or more different views to two or more observers.