The scintillating screen of digital imaging systems used in conventional transmission electron microscopy is discretized and the scintillating material is contained in a cellular structure having a geometry judiciously selected for coupling to the optical channels of the imaging system. This allows optical matching, without smearing, between the elements of the scintillating screen and the discrete light-collecting and light-registering optical channels of the system. Cross-talk among optical channels is consequently minimized and the resulting light-imaging resolution of the digital imaging system is optimized.