Detection circuits (1) for detecting movements of movable objects (2) such as joysticks are provided with detectors (100,200) for detecting movements of the movable objects (2), comprising detection units (101-136,201-204) for detecting light spots (3) from sources (4), the light spots (3) depending on said movements, and with reference detectors (300) for compensating for aging/process variations, comprising reference detection units (301-304) for calibrating the detection units (101-136,201-204). Such detection circuits (1) suffer from aging/process variations to a relatively small extent. First detectors (100) for detecting x or y movements are partly located within the light spot (3) dependently on positions of the joysticks and the reference detectors (300) are then entirely located within the light spot (3) independently from positions of the joysticks. Second detectors (200) for detecting z movements are entirely located within the light spot (3) independently from positions of the joysticks and the reference detectors (300) are then entirely located outside the light spot (3) independently from positions of the joysticks.