# Vectorscope The Vectorscope plots **chrominance** on a circular graph — hue as angle from 0°, saturation as distance from the centre (which represents grey). Use it to evaluate colour balance, skin-tone accuracy, and broadcast-legal saturation. The classic vectorscope is a plot of the **Cb / Cr** plane of Y'CbCr — the two colour-difference signals that, together with luma (Y'), fully describe a video picture. "Zero chroma" is the centre point, which is why neutral grey, 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 centre of the plot for fine colour-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 colour 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 and guide settings

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

Hue Vectors graticule style

Color Wheel graticule style

### Guide Elements | Guide | Description | | ------------------ | -------------------------------------------------------------------------------- | | **HUE Ring** | Colour wheel around the outer edge. Can be **dimmed** for less distraction. | | **Crosshair** | X/Y axis lines through centre | | **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 colour-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 colour 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 % colour-bar targets (default: on) | | **100 %** | Full-level colour-bar targets | Target colour and position are derived from the active colour space. ## Trace Presentation | Setting | Description | | -------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Colorize** | Tint the trace with per-pixel colour (vs. monochrome) | | **Linearise 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 Centre** | Extra gain applied to the low-saturation core (0–12) | ### Highlight Trace Edges Render a coloured 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 colourist uses when talking about lift / gamma / gain. This reveals how colour shifts across shadow, midtone, and highlight regions.

Vectorscope in L/M/H split mode

L/M/H split with Color Wheel graticule

| 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-colour 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.

Zoomed L/M/H split — focus on mids

### 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 colour 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** | Coloured 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 customisable **colour**. ## 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 colour targets across all scopes and layouts. ## Color Pins When colour 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.

Colour pins reflected on the vectorscope

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

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

## Colour 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 colour-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 colour" 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 stylised 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) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.timeinpixels.com/nobe-omniscope/scopes/vectorscope.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.