A method of increasing uniformity in light from a light source at a plurality of targets of the light includes locating a plurality of movable aperture elements between the light source and the targets. Each aperture element defines an aperture through which the light passes from the light source to an associated one of the plurality of targets associated with the aperture element along a longitudinal axis of the aperture element. The method also includes moving at least one of the aperture elements along its longitudinal axis to change a feature of light incident on the target associated with the aperture element.