Lithographic systems and processes of making and using same

A process of operating a lithographic system comprising a projection system having an object field and an image field, the projection system comprising an optical element located at a projection system pupil, the process comprising:

• projecting the object field through the projection system and onto the image field;
• and
• manipulating the projection system pupil via the optical element at normalized pupil heights r=ƒ(ρ) to manipulate an exit pupil of an object point at normalized pupil heights ρ,
• wherein ƒ:
• [0,1]→[0,1] is a non-linear function approximating an offence against the sine condition φP with respect to the projection system pupil.