An illumination apparatus for providing light and for illuminating an illumination plane with a rectangular light distribution is provided. The illumination apparatus includes at least one light source configured to generate light, a collimation optical unit configured to collimate the light, a condenser optical unit configured to shape a rectangular angular distribution of the light coming from the collimation optical unit, and a freeform optical unit having at least one freeform area for modifying the angular distribution such that a rectangular light distribution is produced in an illumination plane that is optically connected downstream.