The chapter addresses microscopy with plasma based laboratory extreme ultraviolet (EUV) and soft-x-ray sources. The
focus is set on the determination of necessary source parameters like radiance and size from fundamental considerations
of the achievable sample resolution, image contrast, detector quantum efficiency and required throughput. The
estimations account for the influence of photon noise on signal detection and conservation of light etendue and radiant
flux. Two cases are considered more detailed – resolution optimized bright field microscopy and sensitivity optimized
dark field microscopy. Inspection of EUV masks and mask blanks required for EUV lithography at 13.5 nm wavelength
is chosen as an illustration for both cases.