Dynamic range refers to the extent of tonal variation a device-such as a scanner, camera, or printer-can capture or reproduce, from the darkest shadows to the brightest highlights. A higher dynamic range means more detail can be retained across the full spectrum of tones.
In scanning, dynamic range is especially important when working with film transparencies or slides, which often contain a wide range of light and dark areas. For example, specialist films like Fuji Velvia have a dynamic range of around 3.7D, so a scanner must match or exceed this range to capture all shadow and highlight details accurately. While less critical for scanning printed images-where the tonal range is already limited-understanding dynamic range is key for achieving high-quality reproductions and preserving the full detail of original images.