Blanking Fill

Blanking Fill does not synthesize new scenery outside the frame. It reuses pixels from the input image and builds a processed background around the primary foreground version of that same source.

That makes source-edge content important. Faces, text, doors, horizons and circular geometry reveal aggressive stretching much faster than sky, walls, bokeh or other low-detail textures.

Read the Inspector from top to bottom as separate jobs: Source prepares the foreground and usable edge pixels; Fill Extent chooses background geometry; Fill Appearance styles the finished fill; Drop Shadow separates the foreground only when needed.

Source Zoom and Zoom Mode are not the same control. Source Zoom changes the foreground/source itself, while Zoom Mode determines how the separate background duplicate covers the blank area.

Crop Left / Right and Crop Top / Bottom are not simply final delivery crops. Inside Blanking Fill they trim the foreground and therefore create or enlarge the area that the fill must rebuild.

Split Left Right and Split Top Bottom unlink the paired crop sides. Keep the linked state for a clean baseline and split only when the composition is genuinely asymmetrical.

Center is visible as a Source control in the current capture. Treat it as a corrective re-centering command after sizing/crop rather than a creative amount control.

The captured Fill Extent section exposes one selector, Zoom Mode, but that selector switches four fundamentally different strategies: Stretch To Timeline, Zoom To Timeline, Manual and Warp Top Layer.

Stretch To Timeline fills the timeline frame by stretching the background duplicate. It guarantees coverage but can visibly distort aspect ratio when recognizable geometry remains in the fill.

Zoom To Timeline preserves the duplicate's proportions and scales it until the frame is covered. The trade-off is proportional cropping at the edges, which is why it is usually the best first mode to evaluate for portrait footage.

Manual is useful when Zoom crops too much but Stretch distorts too much. The project's dedicated ResolveFX Blanking Fill reference records conditional Expand and Aspect controls; establish coverage with Expand first, then judge Aspect separately.

Warp Top Layer is a dedicated edge-warp workflow. Blackmagic's Resolve 16 New Features Guide illustrates this mode stretching image edges into the blanking region; exact current onscreen handle behavior remains a target-build live-verification item.

A narrow source strip usually creates a more aggressive warp, while a wider strip involves more of the original edge area. Always inspect motion because a still frame cannot reveal temporal wobble or distracting stretching.

Set Fill Appearance only after fill geometry is acceptable. Blur Background can make bad geometry less obvious, but it does not fix an incorrect Zoom Mode.

Blend Edges feathers the boundary between the foreground and the generated fill. Excessive values can soften the foreground edge itself, so use only enough to hide a visible seam.

Blur Background affects the background duplicate rather than the primary foreground and is the key control behind the classic blurred portrait-video layout.

Fade Amount is a separate color-overlay stage. At zero the Fade Color has no effect; increasing the amount progressively tints the fill and can approach a solid-color blanking region at the maximum.

Fade Color is not a replacement for proper color correction or color management. It is a styling tint applied to the generated fill.

Drop Shadow is optional. If foreground separation already works through contrast and blur, leaving Shadow Strength at zero is often the cleaner result.

Shadow Strength controls visibility, Drop Angle controls direction, Drop Distance controls offset, Blur controls softness and Color controls tint. Tune them in that logical order rather than moving all five at once.

The current Fusion capture shows Drop Angle 37.5, shadow Blur 0.55 and black Color while Shadow Strength is zero. These values document the captured UI state; they are not universal production presets.

Global Blend is the final dry/wet control for the entire ResolveFX result. Use it only after Source, Fill Extent, Appearance and Shadow already make sense at full effect strength.

Effect Mask is a separate Flow input. It limits spatial coverage of the finished ResolveFX result; it is not a second image source, does not define Warp Top Layer geometry and does not replace source alpha.

Because the foreground and background duplicate are constructed internally, a second MediaIn is not required. Use a manual Transform/Blur/Merge branch when the background needs independent grading, motion, a different source or more complex art direction.

Blackmagic's Resolve 16 New Features Guide explicitly documents Blanking Fill as available on the Fusion page, which is an important boundary: this is ResolveFX hosted inside Fusion rather than a native image generator such as Background.

With transparent upstream material, inspect Alpha Viewer and a contrast-background composite. Blanking Fill is primarily an aspect/blanking convenience effect, so semi-transparent edges still deserve explicit QC.

For mode comparisons, lock the same source frame and Viewer scale. For moving material, also inspect playback and delivery aspect because crop, stretch and warp can look fine on one still and distracting a second later.

The two bundled Fusion screenshots confirm the main Controls panel and the complete Zoom Mode dropdown. Conditional Manual/Warp controls and Global Blend are documented by the project's dedicated ResolveFX reference and remain target-build verification items.