Described herein is a method for calibrating a detector including at least one camera and at least one projector. The projector is configured for illuminating at least one target with at least one predefined illumination pattern including a plurality of illumination features. The camera has at least one sensor element having a matrix of optical sensors, the optical sensors each having a light-sensitive area, where each optical sensor is designed to generate at least one sensor signal in response to an illumination of its respective light-sensitive area by a light beam propagating from the target to the camera. The target includes at least one first target and at least one second target. The first target and the second target have a predefined fixed relative distance. The target is positioned at a pre-defined distance from the detector.