Edge sharpness and enhancement of electron radiographs (ERGs) produced with powder cloud development

Much renewed interest has developed in electrostatic imaging systems. This is partly because of their use of relatively inexpensive materials and their potential for improved diagnostic accuracy--a novel combination of image latitude with great detail contrast. All such systems can exhibit these image characteristics when developed by the generally used "powder cloud" technique or some similar partial development system. We have measured edge sharpness and enhancement of electron radiographs (ERGs) produced with the powder cloud technique. Edge sharpness can be excellent at low image-density levels, but deteriorates with increasing density. Edge enhancement is also appreciable; it appears to decrease somewhat with increasing image density, but no simple relationship has yet been shown.