An apparatus for changing an intensity distribution of a light within an illumination field includes a structure configured to be positioned within the illumination field so that a first portion of the light within the illumination field impinges upon the structure, where the structure is translucent or opaque to a wavelength of the light. The apparatus also includes an actuator configured to cause a movement of a first portion of the structure so that a second portion of the light within the illumination field impinges upon the structure. The light within the illumination field is produced by a source configured so that a pupil fill of a beam of the light is uncontrolled, but the beam of the light downstream of the structure is substantially telecentric before and after the movement of the first portion of the structure. Related methods are also presented.