> For the complete documentation index, see [llms.txt](https://support.4cast.world/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.4cast.world/6.-configuration/display-settings/display-calibration.md). # Display Calibration **Display Calibration** is a visual tool for positioning and resizing the MVP's video output on the physical display. It exists for one main use case: **mapping the output onto irregular or non-standard surfaces** — LED walls, projection scrims, video processors that expect a specific window within a larger canvas, or any scenario where "full-screen at native resolution" isn't what you actually want on the wall. Like [Display Settings](/6.-configuration/display-settings.md), every calibration setting is stored **per display** and automatically reapplied when the same display is reconnected. *** ### Where to Find It 1. Open **System Settings** (gear icon → System). 2. Expand the **Display Settings** panel. 3. Click the **Display Calibration…** button. > The Display Calibration button is enabled only when an HDMI display is connected. If nothing is plugged in, connect a display first. *** ### The Calibration Canvas
The dialog is dominated by a large interactive canvas representing the connected display. * **Outer rectangle** — the physical display, drawn at its full resolution and aspect ratio. * **Inner blue rectangle** — the output rectangle. This is where the video actually appears on the display. A small label in the dialog header shows the canvas size (the display's current resolution). The header label updates if you change the resolution from Display Settings and re-open the calibration dialog. #### Manipulating the Output Rectangle You can adjust the inner rectangle three ways: 1. **Drag the body** — click anywhere inside the rectangle and drag to move it around the display. The rectangle is constrained to the display bounds. 2. **Drag a corner handle** — the four square handles at the corners scale the rectangle. With **Lock aspect** on (default), corners scale proportionally; with it off, each corner moves independently. 3. **Drag an edge pill** — the four thin blue pills on each side resize along a single axis. With **Lock aspect** on, dragging an edge also scales the perpendicular axis proportionally about the rectangle's center. The on-screen video updates **only when you release the mouse,** not during the drag. #### Inspector Panel To the right of the canvas is a numeric inspector with four fields: * **X** / **Y** — top-left position of the output rectangle, in display pixels * **Width** / **Height** — size of the output rectangle, in display pixels You can type values directly, or hover over a field and scroll the mouse wheel: * **Scroll wheel** — adjusts by ±1 per tick * **Shift + scroll wheel** — adjusts by ±10 per tick After a burst of scrolling stops for \~200 ms, the change is pushed to the display. Below the inputs, two status lines show: * **Aspect** — the rectangle's current aspect ratio (e.g., `16:9`). Turns orange and shows "(stretched)" when the rectangle's aspect ratio differs from the display's, which means the video will be horizontally or vertically distorted. * **Coverage** — the percentage of the display's area covered by the output rectangle. *** ### Toolbar Buttons Below the canvas: | Button | What It Does | | ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Reset to 100%** | Returns the output rectangle to fill the entire display (no scaling, no offset). | | **Match {aspect}** | Centers a rectangle of the display's own aspect ratio. When the display is, say, 16:9 and you've stretched the rectangle to 4:3, clicking **Match 16:9** restores a full-display 16:9 rectangle. Disabled when the rectangle is already a full-display match. | | **Lock aspect** | Toggles aspect-ratio locking for drag operations. On by default. With lock on, corner and edge drags preserve the rectangle's current aspect ratio. With lock off, every handle moves independently. | *** ### Applying Changes The dialog has two action buttons at the bottom: * **Cancel** — discards your changes and reverts the on-screen output to the previously-saved geometry. * **Apply** — saves the current geometry to the display's profile and confirms the new output position. The button is disabled until you've made a change. When you click **Apply**: 1. The geometry is persisted to the display's profile file. 2. A snackbar confirms "Display calibration saved." 3. The dialog closes. The change has **already been applied to the screen** during your last drag/release or scroll burst — clicking Apply is what makes it permanent. If you close the dialog with Cancel after making changes, the screen reverts to the saved state. *** ### How the MVP Maps Video onto the Output Rectangle The video frame is always mapped onto the full output rectangle you've drawn — the rectangle is purely a destination, not a crop. Whatever the video resolution is, the MVP stretches or shrinks it to fit your rectangle exactly. This means: * A 1920×1080 video shown in a 960×540 rectangle is scaled down 2× in each axis. No content is lost. * A 1920×1080 video shown in a 1920×540 rectangle is squashed vertically — the same image, half as tall. Aspect ratio is stretched. * An LED wall that takes its input from an HDMI source but only uses, say, the left 1200 pixels of a 1920×1080 signal — set the output rectangle to `X=0, Y=0, Width=1200, Height=1080` and the video fills exactly that area. If you want the video to fill some part of the display without stretching, use **Lock aspect** while you drag, and the rectangle will always preserve the video's aspect. *** ### Related Pages * [Display Settings](/6.-configuration/display-settings.md) — Resolution and refresh rate selection * [System Settings](/6.-configuration/system-settings.md) — Open the gear menu to reach this dialog * [Show Day Checklist](/9.-show-day/show-day-checklist.md) — Verifying display geometry at the venue