Gamut, Legality and Exposure
Seven tools check a picture against a limit.
The Gamut Scope
Section titled “The Gamut Scope”Gamut Scope converts every pixel to CIE xy and classifies it against one target triangle.
- Comfortably inside: neutral grey, [115, 115, 115].
- Close to a rim: orange, [240, 150, 30].
- Outside the target: the color of the rim it crossed, washed a quarter of the way towards white.
Gamut picks the target from Rec.709, Rec.2020, DCI-P3, Adobe RGB, ProPhoto, ACES AP1 and ACES AP0, and starts at DCI-P3.
Near edge is how far inside the rim counts as near, as a share of the target’s extent: 0 to 100%, 15% at stock.
Above 100%, the whole target is inside the band.
The scope paints over the picture. Its target triangle belongs to the CIE Plot, on Histograms, CIE and Plots.
The Out-of-Gamut State
Section titled “The Out-of-Gamut State”Vector checks each frame in the color space it declares, Rec.709 where it declares nothing, against the Gamut target.
A BT.2020 source against Rec.709 or DCI-P3 can cross. Set Gamut narrower than your camera delivers.
Every target contains Rec.709, so a Rec.709 frame shows grey and orange only. Vector then shows a small sentence in weak ink under the Near edge row:
Out of gamut cannot be measured: DCI-P3 contains Rec.709
The target comes first, then Rec.709.
Legality
Section titled “Legality”A level is judged two ways.
- The legal-range line pair: nine kinds show a pair of rules at the picture’s own codes, 64 and 940 or 16 and 235 on the 8-bit scale. It is horizontal across the five waveform kinds and vertical on Luma Histogram, RGB Histogram, Min / Max and Saturation vs Luma. Legal range and Grid both gate it, and both are on at stock.
- The QC luma band: Luma limits on the Error Log is a pair of percentages, 0.0 and 100.0 at stock. The LUMA row judges against it, and the histograms’ Luma band only box counts within it.
The two lines have nothing filled between them. For a delivery check, narrow Luma limits to your delivery band and check the LUMA row on the QC and the Error Log page.
False Color
Section titled “False Color”- False Color owns the ramp picker. Its rows are Family, Preset, Mode, Opacity, Blur with Soft overlay, and Range, the exposure window’s two ends. Mode offers Luma, HDR, Saturation (HSL), Saturation (HSV), Chroma and Hue, and starts at Luma. The ramp is one of 36 presets in four families — Monitors, Exposure Helpers, Camera Log, ARRI LogC4 — and starts at R3D. Changing Family moves to that family’s first ramp. The ruler strip needs Grid on.
- Preview’s False color box paints the same palette. Its one row is Ramp, shown only while the box is on, and its colors come from the default ramp, not from the False Color kind’s Preset.
Zebras, Peaking and Clipping
Section titled “Zebras, Peaking and Clipping”All three are on the picture tile. Zebras, Peaking, Chroma boost and Clip are off at stock, and Channel isolates RGB, Red, Green, Blue or Luma.
- Zebras show two arms on one stripe pattern. One is luma at or above 0.98 of full scale, the 100 IRE zebra, under the frame’s claimed matrix. The other is HSV saturation at or above 0.70, and ignores luma.
- Clipping marks crushed black and clipped white, in blue and red, at the ends of the code range.
- Peaking is a coarse Laplacian edge test on the frame’s own luma, in red, its threshold scaled by the digital zoom.
Mask offers None, 16:9, 4:3 and 2.39:1 and starts at None, and Aspect offers Native, 16:9 and 4:3. The mask, the safe-area guides, the thirds and the centre pan and zoom with the picture.