An electro-optical sensor for use with a retro-reflective target (10). The light-emitting assembly involves a LED (4) and collimating and parallel lenses (2, 4), and the sensing assembly involves a collecting lens (5), an aperture plate (6) and a photodiode array (7) with optional field-curvature correcting lens (8). The lens (5) abut the substrate (1) within the aperture of plate (6) so that the entrance pupil and the exit pupil, when viewed from the target (10), abut opposite, parallel straight-edges of the substrate (1). The photodiode array (7) may be a linear pixel array parallel to the substrate-surface, or may be replaced by a single, large-area photodiode with aperture-limitation of its field of view to a narrow fan-shape parallel to the substrate-surface. A plurality of light-emitters (77) may be used with photo-detectors (71) that have individual light-collection optics (72, 73) with merged fields of view. The sensor can sense golf club-head (100) movement and vehicle speed and plate number (116).