1. A method of determining a structure or process parameter value of a target of interest on a sample, the method comprising: defining a plurality of collection patterns for a spatial light beam controller positioned at a pupil image plane of a metrology tool; for each collection pattern, collecting a signal from a sensor of the metrology tool, wherein each collected signal represents a combination of a plurality of signals that the spatial light beam controller samples, using each collection pattern, from a pupil image of the target of interest, wherein the collection patterns are selected so that the pupil is reconstructable based on the collection patterns and their corresponding collection signals; and analyzing the collected signal for each of the collection patterns to determine a structure or process parameter value for the target of interest.