An invention is described which uses quenchable phosphors to achieve a novel emission response in intensifying screens. The quenchable phosphor has the characteristic of reducing its efficiency of converting incident x-ray, gamma ray, or ionizing particulate radiations into emitted radiation in the ultraviolet (UV), visible or infrared (IR) regions of the electromagnetic spectrum when being essentially simultaneously irradiated by a spectrum of radiation of a specific range in the UV to visible to IR spectrum. The quenchable phosphor is combined with another class of phosphor, which emits the spectrum of radiation when struck by ionizing radiation which is similar or identical to the quenching radiation of the quenchable phosphor. These phosphors can be combined in a variety of geometrical manners, both homogeneously and heterogeneously, to achieve extended dynamic range and spatial frequency filtering for radiographic imaging systems. The invention has equal application for electronic imaging systems such as x-ray image intensifiers. In addition, a system comprising the quenchable phosphors can be built in such a manner as to overcome the optical stage quantum sink limitations in electronic imaging.