An optoelectronic sensor (10) for the detection and distance determination of objects in a monitored area (18) transmits a transmission light beam (14), generates a reception signal from remitted transmission light (20), and determines an object distance from a light time of flight. A reception path between light receiver (24) and evaluation unit (30) is divided into a first and a second partial reception path (46, 48, 50, 52) at a splitter element (44) comprising filtering properties to pass higher frequency parts of the reception signal on to the first partial reception path (46, 48) and lower frequency parts on to the second partial reception path (50, 52). An object's distance is determined from the first and an opacity from the second partial reception signal.