A scanning system for confocal scanning of an object, comprising a light source (1), imaging optics (4) for focusing the light (5) radiated from the light source (1) onto the object (6) to be scanned, and further comprising an image detector (10) for detecting the light (7) from an object point (6') backscattered from the object (6) and passing through the same imaging optics (4). Means (11) for varying the length of the optical path are disposed in the optical path between the aperture array (3) and the object (6), by which means the optical distance of the image plane can be modified in a specific manner, and means are provided to influence the light (5) radiated by the light source onto the object (6) and/or the light (7) reflected from the object (6) and impinging on the sensor (10), in at least one of its characteristics, during an exposure period (t.sub.B1) for acquiring an image, and, during said exposure period (t.sub.B1), a profile holds which states a specific relationship between the characteristic of the light (5, 7) and the optical distance of the image plane from the imaging optics (4), and means (10) are provided which provide a measured value dependent on the characteristics of the light of the trajectory of observation (7) over the exposure period (t.sub.B1), a height coordinate (Z.sub.s) of the object (6) being reconstructable from the measured value achieved during said exposure period (t.sub.B1) and a reference value.