where He is the electron image width, μm; C is constant depending on the EBSD hardware. In our set up, C is 80246 μm. Figure 7 shows that the optimum step size decreases sharply at low magnification and decreases slightly at high magnification. This figure is very useful to find the optimum magnification when a step size is decided. Therefore, it is strongly recommended to have a bigger scan area at high magnification instead of a small area at very low magnification, as schematically shown in Fig. 8.