Exposure systems include a beam generator, which is configured to irradiate source beams in a direction of an object to be exposed by the source beams, along with first and second beam shapers. The first beam shaper, which is disposed proximate the beam generator, has a first aperture therein positioned to pass through the source beams received from the beam generator. The second beam shaper is disposed proximate the first beam shaper. The second beam shaper includes a plate having a second aperture therein, which is positioned to receive the source beams that are passed through the first aperture of the first beam shaper. The second beam shaper further includes a first actuator and a first shift screen mechanically coupled to the first actuator.