Tone mapping

Tone mapping fits an image's light values into the range available for presentation. It can preserve distinctions in bright or dark areas that would otherwise fall outside the display's usable range, although the resulting appearance depends on the chosen mapping.

For example, an HDR image may need its bright highlights compressed for an SDR presentation. This differs from simply clipping all values above a limit to the same white. Tone mapping also differs from brightness upscaling, which raises the brightness of ordinary desktop content.

BetterDisplay's software brightness adjustments do not guarantee a particular content-aware HDR mapping. The content, app, macOS presentation and display all matter. See HDR, Clipping and Apple's EDR explanation.