A detector (110) for determining a position of at least one object (112) is disclosed. The detector (110) comprises: at least one sensor element (118) having a matrix (120) of optical sensors (122), the optical sensors (122) each having a light-sensitive area (124), wherein each optical sensor (122) is configured to generate at least one sensor signal in response to an illumination of the light-sensitive area (124) by at least one light beam (116) propagating from the object (112) to the detector (110); at least one evaluation device (134) configured for evaluating the sensor signals, by a) determining at least one optical sensor (122) having the highest sensor signal and forming at least one center signal; b) evaluating the sensor signals of the optical sensors (122) of the matrix (120) and forming at least one sum signal; c) determining at least one combined signal by combining the center signal and the sum signal; and d) determining at least one longitudinal coordinate z of the object (112) by evaluating the combined signal.