When looking at a radiograph for diagnosis we are looking at different tissues; soft tissue, bone, tooth, enamel, roots and the special periapical tissues. We are also looking for different pathologies including caries, bone loss, fractures, periapical lesions and so on. With an old fashioned film radiograph we have to interpret all of this from a single view. With a digital image we can optimize the image for each tissue and each pathology.
Good radigraphic software should have these optimized views built in., but few do.