HDR10

HDR10 is an open, royalty-free HDR standard defined by the CTA (Consumer Technology Association). It specifies three things: 10-bit color depth (hence the name), the PQ (Perceptual Quantizer) transfer function from SMPTE ST 2084, and static metadata from SMPTE ST 2086 and CTA 861-G that tells the display the mastering display's peak luminance and the content's maximum luminance (MaxCLL) and maximum frame-average luminance (MaxFALL). The PQ transfer function defined in SMPTE ST 2084 is absolute — it maps code values directly to specific brightness levels in nits up to a 10,000-nit ceiling. In a 10-bit PQ signal, the mid-range of the code space (around code value 520) corresponds to roughly 100 nits, approximately the peak brightness of an SDR display, while the upper code values extend all the way to 10,000 nits. This means an HDR10 signal contains significantly more highlight information than SDR, which clips everything above 100 nits. The critical distinction between HDR10 and its competitors: static metadata. HDR10 sends a single set of SMPTE ST 2086 metadata values for the entire program — the display uses these to adapt its tone mapping globally. This means a dark night scene and a bright daytime scene get the same tone mapping instructions. If the content has MaxCLL of 1000 nits, the display maps the entire 0-1000 nit range to its own capability. HDR10+ (Samsung's format) adds dynamic metadata — per-scene or per-frame brightness instructions so the display can optimize tone mapping for each scene individually. Dolby Vision goes further with per-frame dynamic metadata plus 12-bit color depth and a proprietary tone mapping pipeline that can be calibrated per-display model. Mastering targets: most professional HDR content is mastered at either 1000 nits (the standard for streaming and broadcast HDR) or 4000 nits (for premium content on high-end displays). A 1000-nit master means the colorist graded the brightest specular highlights to reach 1000 nits on a calibrated reference monitor. Most consumer TVs can only sustain 500-800 nits peak brightness, so the TV's tone mapping compresses the 1000-nit master down to its capability. The quality of this tone mapping varies enormously between TV manufacturers — a high-end OLED with good tone mapping preserves shadow detail and highlight rolloff, while a budget LCD clips highlights harshly.

The uncomfortable truth: most content labeled as HDR on streaming platforms was graded in SDR and then either automatically converted to HDR or given a minimal HDR pass where someone raised the highlight ceiling to 1000 nits without actually grading for the extended range. Real HDR grading involves making creative decisions about where in the 0-1000 nit range specific elements should sit. A specular highlight on a car window might be pushed to 800 nits while the overall scene luminance sits around 100-200 nits. The contrast between these values is what creates the HDR look — not simply making everything brighter. If the entire scene averages 400-500 nits, you have a bright SDR image, not HDR. True HDR content has an average picture level (APL) of 100-200 nits with carefully placed highlights reaching 4-10x above that. In DaVinci Resolve, the HDR grading workflow starts with enabling HDR in the project settings: Color Science > DaVinci YRGB Color Managed, then set the output color space to Rec.2100 ST.2084 (PQ) with the target peak luminance set to your mastering target (1000 or 4000 nits). Resolve provides dedicated HDR scopes: the HDR scope shows a histogram with nit-based readout instead of IRE, and the CIE chromaticity scope with Rec.2020 gamut boundary overlay. You grade using the standard tools, but now the waveform and histogram are calibrated in nits — you can see exactly where each element falls in the 0-1000 nit range. The biggest practical mistake in HDR grading: pushing the overall image brightness too high. HDR is not about making everything bright — it is about increasing the distance between the darkest dark and the brightest bright while keeping the midtones where they would be in SDR. Skin tones in HDR should sit at roughly the same 40-50 IRE equivalent they do in SDR (around 30-40 nits). The HDR range gives you headroom for specular highlights, practical lights, and sky detail that would clip in SDR — not a mandate to make the entire image brighter.