Abstract: A radiation source directs radiation along a radiation path. An exposure slit positioned along the radiation path directs the radiation at the substrate. The exposure slit has center and edge portions. A lens positioned along the radiation path has an optimal focus position. A support stage supports and moves the substrate relative to the radiation path along a substrate path. The support stage is inclined at a stage angle relative to the radiation path, such that radiation passing through the center portion of the exposure slit contacts the substrate at the optimal focus position of the lens. A filter is positioned along the radiation path and adjacent the exposure slit. The filter transmits more of the radiation at the center portion of the exposure slit relative to radiation transmitted at the edge portions of the exposure slit. A method is also described.