A detector (110, 1110, 2110) for determining a position of at least one object (112) is proposed. The detector (110, 1110, 2110) comprises: at least one transfer device (128, 1128), wherein the transfer device (128, 1128) has at least one focal length in response to at least one incident light beam (116, 1116) propagating from the object (112, 1112) to the detector (110, 1110, 2110); at least two optical sensors (113, 1118, 1120), wherein each optical sensor (113, 1118, 1120) has at least one light sensitive area (121, 1122, 1124), wherein each optical sensor (113, 1118, 1120) is designed to generate at least one sensor signal in response to an illumination of its respective light-sensitive area by the light beam (116, 1116), at least one evaluation device (132, 1132) being configured for determining at least one longitudinal coordinate z of the object (112, 1112) by evaluating a quotient signal Q from the sensor signals. The detector is adapted to determine the longitudinal coordinate z of the object in at least one measurement range independent from the object size in an object plane.