Figure 3

Figure 3

Search of the rotation axis. Minimum intensity projection (each pixel shows the minimum value of the stack calculated along the z direction) of the stack acquired at the angle 0° (a). Minimum intensity projection of the stack acquired at the angle 180° (b). The image shown in b, is flipped horizontally and translated to overlap the image in a. The distance Δx/2 indicates the position of the rotation axis from the image center, along the horizontal direction (c). Blurring artifacts arising from incorrectly identified axial position of the rotational axis z_C (d–f). The contrast of a series of test reconstructions (g) has a maximum at the position corresponding to the correct rotational axis (z_C = 0). Scale bars: 50 µm.