Schematics of the effect of the shadow of the central hole in the mirror. A muon passes through the camera (in brown), before hitting the mirror (in violet), for three different impact distances. The Cerenkov half-light pool emitted below the camera is found between the muon (red arrow) and the outer dashed line. The projected additional shadows (green) depend on the impact distance and the focal distance F of the camera, using Equation (39). Note that the Cerenkov angle has been exaggerated for better visibility.