Gamut

Gamut defines the boundary of reproducible colors within a color space, typically plotted on the CIE 1931 chromaticity diagram. Rec.709 (identical to sRGB gamut) covers about 35.9% of the visible spectrum — this has been the broadcast standard since 1990 and covers most colors you encounter in natural skin tones, common fabrics, and typical environments. DCI-P3 covers approximately 45.5% of the visible spectrum — the extra 26% over Rec.709 is concentrated in highly saturated reds, greens, and cyans that Rec.709 physically cannot reproduce. This is why a P3-graded neon sign or saturated costume looks richer in a theater than on a broadcast monitor — those colors simply do not exist in Rec.709. Rec.2020 (ITU-R Recommendation BT.2020) covers 75.8% of the visible spectrum and is the target gamut for UHD HDR content, but no current display technology can reproduce the full Rec.2020 gamut. The best OLED and quantum-dot displays reach about 80-85% of Rec.2020 (measured as a percentage of the coverage area in CIE 1931). Out-of-gamut colors are colors that exist in your source footage but fall outside the target delivery gamut. When you shoot Sony S-Gamut3.Cine (which exceeds Rec.709 significantly in saturated cyans and greens) and deliver to Rec.709 broadcast, the out-of-gamut colors must be handled somehow. There are two approaches: clipping (hard limit — any color outside the boundary is crushed to the nearest in-gamut color) and mapping (soft limit — out-of-gamut colors are compressed toward the gamut boundary in a way that preserves perceptual relationships). Clipping produces banding and posterization at gamut boundaries. Mapping preserves smoothness but desaturates borderline colors. In DaVinci Resolve, this is controlled under Color Management > Gamut Mapping, with options for Perceptual, Saturation, and Relative Colorimetric. The standard professional workflow: shoot in the widest gamut your camera supports (ARRI Wide Gamut 4, Sony S-Gamut3.Cine, REDWideGamutRGB), process in a wide working gamut (DaVinci Wide Gamut or ACEScg), and convert to the delivery gamut at the end. This gives you maximum flexibility in the grade — you can always throw away color information, but you can never create it retroactively.

Gamut failures show up as three visible artifacts: clipping (hard color banding at saturated edges), hue shifts (colors change their actual hue when they hit the gamut boundary — saturated yellows shifting toward green is the most common example), and desaturation (colors losing vibrancy without the colorist intending it). The worst case is neon signage, LED stage lighting, or intensely saturated costumes shot on a wide-gamut camera. These colors can exceed Rec.709 gamut by 40-60% and produce dramatic artifacts when poorly converted. In DaVinci Resolve, the key to clean gamut conversion is the Color Space Transform (CST) plugin combined with proper Color Management settings. If you are working in DaVinci YRGB Color Managed mode, the gamut mapping happens automatically at the output stage — configure it in Project Settings > Color Management > Gamut Mapping. Set the mapping mode to Perceptual for most content (it preserves the visual relationship between colors while bringing out-of-gamut values inside the boundary). Use Relative Colorimetric only when you need strict color accuracy for in-gamut colors and are willing to accept clipping for out-of-gamut values — this is appropriate for broadcast QC passes where compliance matters more than aesthetics. A practical gotcha: DaVinci Resolve's viewer shows you the output gamut based on your Color Management settings, but the node graph operates in the timeline gamut. If your timeline is DaVinci Wide Gamut and your output is Rec.709, a saturated color that looks fine in the node graph (because it is within the wide timeline gamut) will be compressed at the output stage without any visual warning in the node view. Check the output scopes — the waveform and vectorscope after the output transform — to see what your delivery actually looks like. The CIE chromaticity scope in Resolve is especially useful: it plots every pixel's color on the CIE diagram and overlays the target gamut boundary, so you can see exactly which colors are out of gamut before you render.