Quick answer: build the matte before polishing the composite. Sample the screen in Key, normalize uneven screen color with Pre Matte or a matching Clean Plate, inspect the alpha in Matte, add garbage or solid mattes where geometry is clearer than color, suppress spill in Fringe, and use Tuning only when one tonal range still fails. This specialist guide belongs to the Fusion learning hub and was rechecked on August 26, 2026 against the Resolve 21 Reference Manual and Blackmagic Design's current Fusion overview.
This is the deeper pass: what every tab in the Delta Keyer actually controls, when a clean plate saves the shot and when it makes things worse, how spill suppression really works instead of just cranking a slider, and the on-set lighting mistakes that no amount of Fusion tweaking will fix. If you want the fast version first, Comp 2 in the Fusion tutorial covers that in about a dozen clicks.
DaVinci Resolve Delta Keyer Workflow: The Fast Order
Work through these six tabs in this order and you'll fix most keys without doubling back. Jumping to Fringe or Tuning before the matte is solid usually makes the next tab's job harder, not easier.
- Key tab: sample the screen color and adjust Gain and Balance only enough to get a workable first alpha.
- Pre-Matte or Clean Plate: even out screen color before pushing the main key any harder.
- Matte tab: refine the alpha with Threshold, Restore Fringe, Clean Foreground and Clean Background.
- Mask tab: set how a connected garbage mask clears areas before you grow or fill remaining holes.
- Fringe tab: remove green or blue spill once the matte is solid enough to protect edge detail.
- Tuning tab: adjust shadows, midtones and highlights separately, only when one tonal range keeps breaking.
Delta Keyer Key Tab: Gain, Balance and Background Color
Every Delta Keyer session starts on the Key tab, and most people touch exactly one control there: the Background Color eyedropper. Sample a clean patch of green close to your subject rather than a corner of the frame, and Resolve builds an initial alpha from the difference between that color and the other two channels. That's the entire theory behind a color difference keyer.
Two sliders do the real work once that first pick is in. Gain increases how much influence the sampled screen color has, pushing more of the background toward full transparency. Push it too far and edges around hair or motion blur start disappearing along with the green. Balance controls the mix between the other two color channels the keyer compares against: 0 uses the minimum of the two, 1 uses the maximum, 0.5 splits the difference. On a green screen with warm tungsten spill, nudging Balance away from 0.5 often recovers detail that Gain alone destroys.
Pre-Blur, sitting above both, softens the image slightly before the alpha generates. It's there for noisy or heavily compressed footage, not for fixing a bad key. If you're reaching for Pre-Blur to hide edge problems, the problem is sitting one tab over, in Pre-Matte.
Delta Keyer Pre-Matte Tab and the Clean Plate Node
Pre-Matte exists because a single background color pick rarely matches every patch of a real screen. Shadows, wrinkles, and uneven lighting read as different shades. Switch View Mode to Pre Matte, box-select screen areas that differ from the first pick, expand the selection with Soft Range, and use Erode to keep the range from clipping subject edges. Lock Color Picking after the range is established so an accidental drag doesn't expand it.
A Clean Plate node solves the same problem from a separate branch. Feed the green- or blue-screen source into both Clean Plate and Delta Keyer, then connect Clean Plate output to the Delta Keyer's magenta Clean Plate input. In Clean Plate, Method offers Color for an even screen or Ranges for a shadowed/mixed screen; Matte Threshold, Erode, Grow Edges and the Fill checkbox build the plate. Sequence generates it per frame, while Hold Frame uses one frame. A separately recorded empty screen is useful only when camera, focus, screen and lighting still match the performance shot.
A matching clean plate helps normalize uneven screen color, wrinkles, gradients, reflections, and screen variation behind fine hair, smoke, or motion blur so the keyer can preserve delicate transparency without choking the matte. It does not remove green light already cast onto skin, restore foreground detail already clipped by Threshold, or compensate for a plate whose camera or lighting no longer matches the shot.
Use a clean plate only when it improves the alpha across the full shot. A good direct key on an even screen doesn't need one; a mismatched or overgrown plate can introduce new edge and transparency errors.
Delta Keyer Matte Tab: Threshold, Erode and Restore Fringe
Switch View Mode to Matte and display the alpha channel before touching Threshold. The Low Threshold handle turns values below it black and transparent; the High Threshold handle turns values above it white and opaque. Values between them keep their relative transparency. Move only as far as the shot requires: aggressive Low Threshold loses hair and motion blur, while aggressive High Threshold can merge fine detail into the solid foreground.
Restore Fringe can bring back legitimate soft edge detail lost during thresholding while keeping the matte core solid. Erode/Dilate expands or contracts the matte, and Blur softens it. Clean Foreground fills slightly transparent light-gray areas that should be opaque. Clean Background clips the lower dark range that should be transparent. Apply small changes while watching both the alpha and Final Result; none of these controls knows which gray pixels are hair and which are noise.
Replace Mode controls how matte adjustments restore color: None makes no color replacement, Source uses the original image, Hard Color uses a solid replacement, and Soft Color weights that color by how much background was removed. Choose by inspecting the final composite; a mode that fills the alpha but adds noisy or artificial edge color isn't a clean result.
Delta Keyer Mask Tab: Solid and Garbage Mattes
Garbage Matte and Solid Matte are inputs on the Delta Keyer node itself, not settings inside a tab. Connect a shape or paint mask to the Garbage Matte input to force an area, a light stand, a mic, the edge of the screen, to full transparency regardless of what the key decides. Connect a shape to the Solid Matte input to force an area to stay fully opaque, useful when spill or a rough key keeps punching a hole through part of your subject.
The Mask tab determines how the connected solid and garbage mattes combine with the key. Solid Source Alpha can ignore, add, or subtract the source alpha; Solid Replace Mode and Color control how forced-opaque areas restore color; Garbage Mask Invert swaps which side is removed. It doesn't control the Clean Plate node’s Grow Edges or Fill operations.
A clean garbage matte drawn around an obvious problem fixes more of a bad-looking key than another pass of Gain or Threshold ever will.
Delta Keyer Fringe Tab: Spill Suppression Settings
Spill is screen color visible through semi-transparent edge pixels or reflected onto the subject. The Fringe tab handles most Delta Keyer spill suppression. Spill Method chooses algorithm strength: Rare is lightest, Medium is documented for green screens, Well Done for blue screens, and Burnt for troublesome blue-screen material. Spill Suppression controls the amount. Raise it only until the unwanted screen color recedes; excessive suppression can bleach legitimate foreground color.
Fringe Gamma adjusts the brightness of the fringe or halo. Fringe Size expands or contracts that region, while Fringe Shape pushes it toward the outer or inner edge. The Cyan/Red, Magenta/Green and Yellow/Blue controls color-correct remaining semi-transparent edge pixels toward the new background. These are different jobs, so change one while comparing the alpha and final composite.
Don't mix Delta Keyer labels with the Color page's 3D Keyer terminology. Matte Finesse is used in the Color-page workflow; Delta Keyer exposes Matte and Fringe controls with different names. The Color grading guide covers qualifiers and windows when the task is a selection rather than a Fusion key.
Delta Keyer Tuning Tab: Shadows, Midtones and Highlights
Tuning divides the image into shadow, midtone and highlight ranges and lets matte strength and spill suppression vary by tonal value. Use it only after Key, Pre Matte/Clean Plate, Matte and Fringe are behaving. Dark hair, bright edges or noisy midtones can still be caused by a bad sample, clipped Threshold or an uneven screen; they aren't automatically Tuning problems.
Lock Alpha/Spill Removal Tuning applies the same tonal ranges to alpha generation and spill removal while it's enabled. Disable it when the two jobs need different ranges, for example stronger alpha work in the shadows without equally strong color subtraction there. Simple sets linear ranges; Smooth creates a smoother tonal gradient. Start with those shapes before hand-adjusting every range control.
Leave this tab alone on a well lit shot. It earns its place only when a specific tonal range keeps breaking after Matte and Fringe are already dialed in.
Edge Integration After the Key
Delta Keyer finishes the alpha and spill work; it does not automatically match the subject to a new background. After the key is stable, compare black level, white balance, contrast, sharpness, grain, and edge light with the destination plate. Make those adjustments on clearly labeled downstream branches so the matte remains inspectable.
A subtle background-colored edge treatment can help when the destination actually casts that light, but it must follow the new scene’s direction, color, and softness. If the treatment creates a glowing outline or hides a broken alpha, remove it and repair the Matte or Fringe stage instead. This guide doesn't prescribe one universal light-wrap node recipe because the correct build depends on the shot and composite.
Green Screen Lighting Mistakes That Break the Key
A difficult screen can consume far more cleanup than a well-prepared one. Uneven illumination, wrinkles, reflective contamination, and subject shadows all create screen colors that one sample may not cover. Reduce those differences on set, keep the backing out of focus where the shot allows, and record a matching clean reference when the setup is static enough to make it useful.
Subject-to-screen distance matters because closer placement usually increases green or blue bounce onto skin, hair, and clothing. Move the subject far enough from the backing for the actual lens, screen size, room, and lighting setup; there's no universal distance that guarantees a clean result. Light the screen and subject as separate jobs, and avoid subject shadows on the backing whenever possible.
If you're troubleshooting a key that fights you at every tab, check these three things before opening the Inspector again. A clean plate helps a lot with uneven lighting. It does nothing for spill, and it does nothing for a shadow problem that needed a second light on set.
Delta Keyer Performance on Heavier Composites
A larger keying tree can reduce interactive playback, especially with multiple keyers, a Clean Plate branch, edge work, and high-resolution footage. Use a lower viewer proxy only while adjusting, then inspect the full-resolution alpha and final composite before approval. The Resolve system-requirements guide covers the wider decode, memory, and GPU context; smooth proxy playback isn't proof that fine hair, motion blur, or noise survived the key.
Once the matte, spill correction, and edge integration are locked, the composite returns to the Edit page like any other shot. The DaVinci Resolve export workflow covers the delivery stage; recheck the full-resolution composite before rendering.
Delta Keyer FAQ
What's the difference between the Delta Keyer and the Chroma Keyer in Fusion?
Delta Keyer is an advanced color-difference keyer optimized for blue and green screens, with Pre Matte, Clean Plate, Matte, Fringe and Tuning controls. Chroma Keyer can target another chosen color with a simpler control set. Use the tool whose controls match the shot rather than assuming one keyer wins every source.
Do I need a clean plate for every green screen shot?
No. A Background Color sample can handle an even screen. Use a matching Clean Plate when screen variation would otherwise force aggressive matte cleanup and the plate preserves useful soft detail. It cannot restore detail already clipped by Threshold or remove screen-colored light reflected onto the subject.
Why does my key still show green on hair after adjusting the Fringe tab?
Inspect the alpha first. If Threshold removed the hair detail, use less aggressive thresholding and Restore Fringe before increasing spill suppression. Once the matte contains the legitimate semi-transparent edge, use Fringe controls to correct remaining screen color.
Can the Delta Keyer key a blue screen the same way it keys green?
Yes. Sample the blue screen and use the same Key, Pre Matte or Clean Plate, Matte, Mask, Fringe and Tuning workflow. The settings remain shot-specific. Blackmagic spells out Well Done for blue screens and Burnt only for troublesome blue-screen material.
Why does my Delta Keyer key show black splotches or noisy edges?
Check the alpha to identify whether the defect comes from source noise/compression, an uneven screen, the Pre Matte selection or aggressive Threshold. Pre-Blur can help certain source noise and edge artifacts, but use it sparingly. Clean Foreground, Clean Background or a second specialized key should follow the diagnosis, not replace it.
Is the Delta Keyer available in the free version of DaVinci Resolve?
Yes. Delta Keyer, Clean Plate, garbage and solid mattes and the core Fusion keying workflow are available in Resolve Free. Studio adds other Neural Engine, effects and workflow features; verify the current boundary in Blackmagic Design's feature comparison if another tool in the composite is the reason for upgrading.
Related guides
- Fusion in DaVinci Resolve: the hub: the rest of the Fusion cluster.
- DaVinci Resolve Fusion Tutorial for Beginners: start here if Merge nodes are still new.
- How to Color Grade in DaVinci Resolve: qualifiers and windows, for when you need selection rather than a key.
