Over the past 15 years, ptychography applications and methods have advanced significantly. Ptychography is a computational microscopy technique for acquiring images with resolutions beyond the limits imposed by beam diameter, optical aberration, and numerical aperture—NA, a measure of the range of incident angles an optical system can accept. Nowadays it encompasses various experimental techniques with visible light, UV light, x rays, and electrons. Emerging applications include, for example, accurate wavefront-aberration measurement for space telescopes.