Extended (unbounded) color range allows values outside 0–1 for HDR and wide-gamut workflows

Normally color channels are clamped to [0, 1]. In extended-range mode, values outside this range are permitted: values above 1.0 represent intensities brighter than nominal white; negative values represent imaginary colors outside the gamut. Extended range is used in HDR pipelines and wide-gamut compositing as intermediate computation values before the final transform clips them to the display’s native space. Caveats: unbounded values can be physically meaningless (−1,−1,−1), and they cannot be stored in 8-bit formats.

Examples

A wide-gamut intermediate color R=1.47 is valid during compositing; it clamps to 1.0 only at the final sRGB output stage.

Assessment

Give one reason to use extended-range color values in a rendering pipeline, and one reason to be careful about them.