High Dynamic Range, or HDR, refers to the extended span of brightness values ( from the deepest shadows to the brightest highlights ) that an imaging system can capture, process, or display. In photography and cinematography, dynamic range describes the ratio between the brightest and darkest tones a sensor can record simultaneously without losing detail. In display technology, HDR specifies the ability of a screen to reproduce a wider range of luminance than standard dynamic range displays, showing brighter highlights, deeper blacks, and more detail in both extremes simultaneously.
In camera capture, a high dynamic range means the sensor can retain detail in a bright sky while simultaneously preserving shadow information in a dark interior: a challenging scenario where a standard-dynamic-range camera would either blow out the sky or crush the shadows to black in order to expose the other correctly. Professional cinema cameras are valued for their ability to capture 12, 14, or even more stops of dynamic range, giving colourists the raw material to bring out detail across the full tonal spectrum in post-production. Log encoding formats, used by cameras from Sony, ARRI, Canon, and others, compress wide dynamic range information into a colour space that the camera can record and that preserves the full extent of captured tonal data for later grading.
In display terms, HDR standards such as HDR10, Dolby Vision, and HLG specify the peak brightness levels, colour gamut, and metadata formats that allow HDR-capable televisions and monitors to display content with greater tonal depth than standard dynamic range screens. HDR streaming content from platforms such as Netflix and Apple TV+ is mastered to these specifications and delivers a substantially richer viewing experience on compatible displays: with specular highlights that genuinely appear to glow and shadow areas that retain visible texture.
In AI image and video generation, HDR is relevant both as a production standard for the intended delivery environment and as a stylistic descriptor in prompts. Including HDR in prompts often steers models toward generating images with a wider tonal range, more luminous highlights, and richer shadow detail, though the actual dynamic range of the generated file is constrained by the standard display format in which it is saved.
