D-max (short for maximum density) is a term used in photography to describe the darkest part of an image or negative-the area that transmits or reflects the least amount of light. It is a key factor in determining the contrast and tonal range of film, prints, or digital scans. A higher D-max allows for richer blacks and deeper shadows, contributing to more dynamic and visually striking images. Understanding D-max helps photographers control exposure, development, and printing processes to achieve balanced, high-quality results.