An exposure system for manufacturing flat panel displays (FPDs) includes a reticle stage and a substrate stage. A magnification reflective optical system images the reticle onto the substrate. The system may be a 2× magnification system, or another magnification that is compatible with currently available mask sizes. By writing reticles with circuit pattern dimensions that are one-half the desired size for an FPD, a 2× optical system can be used to expose FPDs. The designs for the 1.5× and larger magnification optical systems all typically have at least three powered mirrors. A corrector, positioned either near the reticle or near the substrate, can be added to the three mirror design to improve the systems optical performance. The corrector may be a reflective, or a refractive design. The corrector can have an aspheric surface, and optionally a powered surface.