The synchrotron based X-ray diffraction method “High angular resolution 3DXRD” is briefly introduced. The technique enables the investigation of individual dislocation free regions in a dislocation structure, in-situ within the bulk. Results on the strain distribution within a single grain in a copper sample deformed in tension to 2%, and kept under load, are presented. It is found that the dislocation free regions of the dislocation structure on average are subjected to compressive strain with respect to the mean (tensile) strain in the grain. Results on the dynamics of individual dislocation free regions during straining are further reviewed, with special focus on the observation of intermittent behaviour.