Multipath is a prominent phenomenon in Time-of-Flight camera images and distorts the measurements by several centimetres. It troubles applications that demand for high accuracy, such as robotic manipulation or mapping. This paper addresses the photometric processes that cause multipath interference. It formulates an improved multipath model and designs a compensation process in order to correct the multipath-related errors. A calibration of the ToF illumination supports the process. The proposed approach, moreover, allows to include an environment model. The positive impact of this process is demonstrated.