The nature of the electrophotographic image when dual-layer organic photoconductors are exposed to digital input is different than that of images obtained with analog input on account of several considerations: (1) reciprocity, (2) space-charge-limited discharge, (3) optical interference effects, and many others. Reciprocity and space-charge-limited conditions result from short exposure times. Reciprocity refers to the change in the efficiency of the supply of carriers from the generator layer into the transport layer. Although, on the basis of theoretical considerations, there could be either an increase or a decrease of supply efficiency, most published results show a reduction in sensitivity. This reduction has been ascribed to Langevin recombination effects. In the limit of space-charge-limited discharge, there is considerable lateral motion of the charge carriers (due to their mutual Coulomb repulsion) during their transit through the transport layer, resulting in loss of resolution, which can also occur in analog exposure through electric field distortion during exposure. Coherent light interference leads to a print pattern in the background.