> For the complete documentation index, see [llms.txt](https://docs.timeinpixels.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.timeinpixels.com/nobe-omniscope/scopes/vectorscope.md). # Vectorscope The Vectorscope plots **chrominance** on a circular graph — hue as angle from 0°, saturation as distance from the center (which represents gray). Use it to evaluate color balance, skin-tone accuracy, and broadcast-legal saturation. The classic vectorscope is a plot of the **Cb / Cr** plane of Y'CbCr — the two color-difference signals that, together with luma (Y'), fully describe a video picture. "Zero chroma" is the center point, which is why neutral gray, white, and black of every level all collapse to a single dot there.

Vectorscope with 75 % targets, skin-tone line, and I/Q guides

Vectorscope features: Color Wheel mode, hexagonal rings, trace outline, skin-tone tolerance band, improved target indicators, and I/Q lines

## Transform Modes | Mode | Description | | ------- | --------------------------------------------------------- | | **YUV** | Classic broadcast vectorscope (CbCr plane). Default. | | **HSL** | Saturation-weighted projection — useful for look-dev work | You can switch **Orientation** to the alternate rotation mode in either transform mode. For a color-wheel-style orientation, use **HSL** transform with the alternate orientation mode. ## Zoom Zoom into the center of the plot for fine color-balance work or expand to see the full gamut. | Input | Action | | ------------------------------------ | -------------------------- | | **Mouse wheel** | Zoom in / out (continuous) | | **Middle-click** or **Double-click** | Reset to 100 % |

Zoomed vectorscope for precise color balance inspection

Context-menu presets: **100 %** and **200 %** for quick switching. ### Input Gain Boost the trace intensity to reveal low-saturation detail. | Input | Action | | --------------------------------------------------- | ------------------- | | **Mouse wheel** (with **Mouse wheel gain** enabled) | Adjust gain (1×–5×) | | **Middle-click** or **Double-click** | Reset gain to 1× | Enable **Mouse wheel gain** in the scope settings to switch the scroll wheel from zoom to gain control. ## Graticule & Guides

### Graticule Style | Style | Description | | --------------- | ---------------------------------------------------------- | | **Standard** | Circular rings with crosshair, I/Q lines, and target boxes | | **Hue Vectors** | Gradient-based hue visualization with directional vectors | | **Color Wheel** | Full color wheel background for intuitive hue reference |

### Guide Elements | Guide | Description | | ------------------ | -------------------------------------------------------------------------------- | | **HUE Ring** | Color wheel around the outer edge. Can be **dimmed** for less distraction. | | **Crosshair** | X/Y axis lines through center | | **Rings** | Saturation reference rings. Toggle between **circular** and **hexagonal** paths. | | **I/Q Lines** | In-phase / Quadrature axis guides | | **Outer Scale** | Tick marks around the outer ring | | **Vectors** | Broadcast color-bar target markers | | **Skin-tone Line** | Configurable reference line at a user-defined hue angle (default 123°) | ### Skin-Tone Indicator Band The skin-tone line can be expanded into an optional tolerance band. This helps you quickly see whether skin hues stay close to your chosen reference angle. | Setting | Description | | ------------------------ | ------------------------------------------------------------------------ | | **Show Fleshtone Line** | Enables the skin-tone reference axis | | **Fleshtone Angle** | Sets the reference angle (0–359°, default 123°) | | **Show Tolerance Band** | Draws a shaded angular band around the reference line | | **Tolerance** | Band half-width in degrees (±1° to ±45°; common values are ±10° or ±20°) | | **Tolerance Band Color** | Adjust band color and opacity for visibility |

Skin-tone tolerance band on the vectorscope

Interpretation: trace energy inside the band is within your current skin-tone tolerance; trace energy outside the band indicates hue drift from that reference. ### Broadcast Targets | Target | Description | | --------- | --------------------------------------------- | | **75 %** | Standard 75 % color-bar targets (default: on) | | **100 %** | Full-level color-bar targets | Target color and position are derived from the active color space. ## Trace Presentation | Setting | Description | | -------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Colorize** | Tint the trace with per-pixel color (vs. monochrome) | | **Linearize trace** ("De-gamma") | Apply the inverse EOTF to the trace-density accumulator so that the visual brightness of the plot follows light-linear energy instead of the non-linear R'G'B' code values. Makes shadow-region and highlight-region saturation appear with similar visual weight — useful for log or HDR signals where a raw trace would be dominated by midtone density. It does **not** change the chroma position of any sample, only how brightly it is drawn. | | **Smooth Trace** | Temporal blend for a cleaner, less noisy look | | **Enhanced Render** | Line-strip rendering instead of point cloud | | **Gain** | Master trace brightness (0.02–3.0) | | **Enhance Center** | Extra gain applied to the low-saturation core (0–12) | ### Highlight Trace Edges Render a colored outline at the outermost boundary of the trace — highlights the signal extent at a glance.

Trace edge highlight showing signal boundary

## Split Tones (L/M/H) Split the trace into three independent **Lows / Mids / Highs** buckets, each drawn in its own circle. Buckets are defined by **luma** (Y', the weighted R'G'B' sum — not scene-linear luminance), so the split follows the same tonal perception a colorist uses when talking about lift / gamma / gain. This reveals how color shifts across shadow, midtone, and highlight regions.

| Setting | Description | | ------------------- | ---------------------------------------------- | | **Split L/M/H** | Enable the three-way split | | **LM ratio** | Boundary between Lows and Mids (default 33 %) | | **MH ratio** | Boundary between Mids and Highs (default 66 %) | | **Ring brightness** | Adjust graticule brightness per bucket | | **Enhanced render** | Sharper rendering for split view | ### L/M/H Preview Hold **Alt** to see a false-color overlay on the Source Signal showing which pixels fall into each luma range — blue for lows, green for mids, red for highs.

L/M/H preview overlay showing luminance ranges on the source image

### Zoomed L/M/H Use the standard vectorscope zoom controls while inspecting the split circles.

### Luma Range Clamp Instead of splitting into three buckets, clamp to a **single luma range** using the **Min / Max** sliders. Only pixels whose Y' falls within the range are plotted — useful for isolating the color of skin pixels, of highlights alone, or of a specific zone of the image without masking. ## Saturation Alerts Set thresholds to flag illegal or excessive saturation levels.

Saturation alert ring and max ring indicators

| Alert | Description | | -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------- | | **Alert Ring** | Colored ring at a configurable saturation threshold. Signal exceeding it triggers a visual warning. Drag the ring interactively to reposition. | | **Max Ring** | Tracks and displays the absolute maximum saturation contour in real time | | **Outline** | GPU-rendered trace boundary with anti-aliasing. Use the **Outline Thickness** slider to adjust the rendered width (0.5–5 px). | Each alert has a customizable **color**. ## Low-Pass Filter Enable **Low-Pass filter** to apply a horizontal box blur to the trace, reducing noise and making trends easier to read. Adjustable kernel size (0.5–20). ## Global Targets [Global targets](/nobe-omniscope/features/global-targets.md) appear as RGB reference points on the vectorscope, providing shared color targets across all scopes and layouts. ## Color Pins When color pins are placed on the [Source Signal](/nobe-omniscope/scopes/source-signal.md), they appear as markers on the vectorscope at the corresponding hue/saturation position.

Right-click any color pin on the vectorscope to **Set as custom target** — a quick way to turn a sampled color into a [global target](/nobe-omniscope/features/global-targets.md) without manually entering values.

Right-click a color pin to set it as a custom target

## Color Space The vectorscope defaults to the working signal. Use **Color Space Transform override** in Source & Input to evaluate the trace in a selected working/display transform. ## Skin-Tone Practice Skin tones usually align close to the **skin-tone axis**, a reference direction inherited from the NTSC I/Q color-difference system. I and Q were axes rotated 33° from Cb/Cr to align the high-bandwidth **I (In-phase)** axis with the orange/cyan "memory color" line that human vision is most sensitive to — and the **-I** direction corresponds roughly to human skin. Most properly exposed skin falls within \~10–20° of that axis regardless of complexion; only hue balance differs, not the underlying axis. Creative and regional preferences still apply, so use the tolerance band as a visual guide, not a hard rule. A heavily stylized grade will deliberately pull skin off-axis. ## Keyboard Shortcuts | macOS | Windows | Action | | ------------ | ------------ | ------------------------------- | | Mouse wheel | Mouse wheel | Zoom (or Input Gain if enabled) | | Middle-click | Middle-click | Reset zoom / gain | | Alt (hold) | Alt (hold) | Preview L/M/H split ranges | ## StreamDeck / Action Editor | Action | Description | | ------------------- | ----------------------------------------------------------- | | **VectorScopeZoom** | Button: toggle 1×/2× zoom. Dial: fine zoom (±5 %, 35–500 %) | | **VectorToggleLmh** | Toggle Split L/M/H mode | ## Related * [Global Targets](/nobe-omniscope/features/global-targets.md) * [Gamut Check](/nobe-omniscope/qc/gamut-check.md) * [Skintone Scope](/nobe-omniscope/scopes/skintone-scope.md) * [Available Actions](/nobe-omniscope/streamdeck/available-actions.md)