The two-particle model describes the approach of particle centres and the growth of the interparticle contacts during sintering of metal powders. Unfortunately the comprehensive description of processes inside of three dimensional specimens must consider the contribution of particle rearrangements. The recent developments of combined micro focus computed tomography (CT) and 3D photogrammetric image analyzing give the opportunity to obtain the experimental data required to overcome the shortcomings of sintering theories based on the two-particle model. The analysis of spherical poly and single crystalline copper powder was performed by CT. In addition a single crystal specimen was analyzed by high resolution synchrotron radiation tomography - a more sophisticated analysis method with very limited availability. The analysis of the 3D tomographic image by photogrammetric image analyzing yielded the positions and radii of all particles and their contact partners as well. A statistical analysis of the retrieved data was performed. The formation and breaking of necks during sintering could be observed. An in-depth analysis of the particle rotation with respect to the coordination number and local density will be presented.