Fig. 11

The images at near and distant focus taken with blue (top), green (middle), and red (bottom) filters. In quantitative analyses, the cross-correlation coefficient was 0.907 at distant focus and 0.914 at near focus with a blue filter. The cross-correlation coefficient was 0.872 at distant focus and 0.910 at near focus with a green filter. The cross-correlation coefficient was 0.888 at distant focus and 0.906 at near focus with a red filter