To measure grain orientation in SEM with high accuracy a new EBSP calibration software is developed. Grain orientation determination is simply based on marking three zone axes in the live EBSP. The EBSP-technique has been applied to study misorientation between subgrains in high purity and commercially pure aluminium. The lattice curvatures, which develop during deformation, increase with the amount of deformation. During annealing the subgrains grow, resulting in an increased average neighbouring misorientation due to misorientation accumulation.