This presentation explores the distinctions between the contrast present in the projected image as it reaches the receptor, the latent image stored by the receptor and the displayed image after digital processing. The presentation also covers how the position, breadth, height and shape of the digital image histogram are interpreted, the effects of windowing and digital processing, and common misconceptions about the relationship between contrast and the histogram. The effect of high kVp and the exposure latitude of digital technology on patient dose are also explained.