Depth cameras are increasingly used for tasks such as 3-D reconstruction, user pose estimation, and human- computer interaction. Depth-camera systems comprising multiple depth sensors require careful calibration. In addition to conventional 2-D camera calibration, depth correction for each individual device is necessary. In this paper, we present a new way of solving the multi depth-camera calibration problem. Our main contribution is a novel depth correction approach which supports the generation of a 3-D lookup table by incorporating an optical marker-based tracking system. We verify our approach for the Microsoft Kinect and for the MESA Swiss- Ranger4000 time-of-flight camera.