Figure 5.

(a) Absorption contrast and (b) Zernike phase contrast of a Siemens star. The <50 nm lines (third inner ring, red arrow) are clearly resolved in both images. The half-period resolution (as determined by FRC) for (a) is 48.1 nm ± 1.6 nm and for (b) is 47.2 nm ± 2.5 nm.