“…However, for single photon counting applications, a maximum of one photon is collected per pixel per frame, and with photon counting approaches where the photon events cover an area bigger than one pixel, the resolution of the image does not need to be limited by the sensor pixel size. A characteristic feature of this method is the possibility of employing a centroiding technique, where the position of a photon event can be determined with sub-pixel accuracy [ 52 , 53 , 54 , 55 , 56 ]. With EB-sensors, centroiding can be used to recover the resolution lost in the electron diffusion process, and the resolution of the image is then limited by the photoelectron trajectories from the photocathode to the sensor, governed by the proximity focussing principle [ 26 ].…”