I keyed an interview shot last year that looked perfect in the viewer for about 11 seconds, then fell apart the moment the subject leaned forward under the key light. The green screen behind her wasn't lit evenly, and the quick version of the DaVinci Resolve Delta Keyer setup, drop the node in, sample the green, done, left a visible seam across her shoulder every time she moved. That's the version most tutorials show you, including the quick first key in our own Fusion tutorial. It gets you a working key in 4 minutes. It does not get you a key that survives a client review.
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.
DaVinci Resolve 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.
DaVinci Resolve 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 green screen. Shadows, wrinkles and uneven lighting all read as slightly different shades of green, and the Key tab's one sample point can't account for that. Switch the Inspector's view mode to PreMatte Out, then box-select the patches of screen that look off. Soft Range expands how far that selection reaches, and Erode pulls the edge back in when it starts eating into your subject.
A Clean Plate node solves the same problem from the other direction. In Fusion, you typically branch the same green screen clip into both a Clean Plate node and the Delta Keyer, rather than shooting separate empty-screen footage. The Clean Plate node builds a reference image of the screen color using its own Erode and Grow Edges controls, and its output connects to the Delta Keyer's Clean Plate input. If you did shoot a few clean seconds of the empty screen before your subject walked in, that footage can give the Clean Plate node a better starting point, but the connection matters more than the source: Clean Plate output into the Delta Keyer's Clean Plate input, every time.
A clean plate helps with uneven screen color, wrinkles, gradients and shadowed patches on the backing itself. It does nothing for green spill on skin, a subject standing too close to the screen, or a shadow the subject casts. Those are Fringe tab, Matte tab, or on-set lighting problems, not clean plate problems.
Skip the clean plate on a screen with visible wrinkles or a gradient from top to bottom lighting, and you're stuck fighting the Pre-Matte tab shot by shot instead.
DaVinci Resolve Delta Keyer Matte Tab: Threshold, Erode and Restore Fringe
Switch the viewer to display the alpha channel before touching this tab. You need to see black, white and gray, not the color image. Threshold has two handles: drag the low end up to push background gray toward solid black, drag the high end down to push foreground gray toward solid white. Most keys need both handles moved at least a little.
Restore Fringe is the control people miss. Hair and semi-transparent edges get clipped out during thresholding, and Restore Fringe brings that detail back without reopening the matte everywhere else. Erode/Dilate then shrinks or grows the whole matte, and Blur softens it. Clean Foreground fills in the light gray holes that show up inside a solid subject, usually from spill reflecting inside clothing folds. Clean Background does the same job on the far side, clipping stray light gray in what should be solid black.
Replace Mode decides what color fills in wherever these adjustments recover pixels that Threshold originally keyed out. Source uses the original footage, Soft Color blends a solid color based on how much green was removed there. Leaving Replace Mode on the default is fine for a first pass, but if noise shows up in midtone browns and grays after cleanup, that's usually where it came from.
DaVinci Resolve 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 itself controls how that connected garbage mask behaves once it's wired in. It inverts the mask when needed and sets whether the garbage mask clears its area before or after you grow edges and fill remaining holes on the Matte tab. Wire the garbage mask in first, then check the Mask tab if the cleared area looks inverted or fights your erode and fill settings instead of working with them.
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.
DaVinci Resolve Delta Keyer Fringe Tab: Spill Suppression Settings
Spill is green light bouncing off the screen and landing on your subject, most visible along hair and shoulders as a faint green tint. The Fringe tab handles most of it. Spill Method picks the algorithm strength: Medium works for the majority of green screen shots, Well Done and Burnt exist for blue screen and stubborn footage. Spill Suppression is the amount, and it's the slider most tutorials tell you to crank when green survives on hair. Crank it too far instead and color bleaches out of the subject entirely, including skin tones that were never part of the problem.
Fringe Gamma, Fringe Size and Fringe Shape control where that correction applies rather than how strong it is, useful when spill sits right at the edge of the matte instead of spread across a wider halo. The Cyan/Red, Magenta/Green and Yellow/Blue sliders below them do targeted color correction on whatever fringe remains, matching semi-transparent edge pixels to the new background instead of the old green one.
One thing worth separating in your head: "Matte Finesse" is the name Resolve uses for edge refinement on the Color page's 3D Keyer and Qualifier, Clean Black, Clean White, Blur Radius, In/Out Ratio. The Delta Keyer's Matte and Fringe tabs do the equivalent job with different names and finer control. If a guide you've read mixes the two terms up, that's why the wording doesn't match what you're seeing in Fusion.
DaVinci Resolve Delta Keyer Tuning Tab: Shadows, Midtones and Highlights
Tuning is the tab most people never open, and it's the one that fixes a key that's mostly right except for one tonal range. It splits the image into shadow, midtone and highlight zones and lets you control matte strength and spill suppression separately for each. Dark hair getting eaten by the key, bright edges refusing to lose their green, midtone clothing picking up noise after cleanup: these are Tuning problems, not Matte or Fringe problems.
Lock Alpha/Spill Removal Tuning stays on by default, which applies the same tonal ranges to both the alpha and the spill calculation. Unlock it when you need different behavior for each, for example a stronger matte in the shadows while keeping spill suppression lighter there, so dark hair doesn't lose its color along with the green. The Simple and Smooth buttons set a linear or a smoothed gradient across the ranges as a starting point, worth trying before hand-adjusting the range sliders.
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.
DaVinci Resolve Light Wrap: Blending Edges Without a Dedicated Node
The stock Fusion toolset doesn't include a single Light Wrap node the way it includes a Delta Keyer. Free community macros exist if you'd rather drop one in, but built from the nodes already in front of you, it takes about 4 nodes once you know the order. Invert your keyed subject's alpha channel, apply that inverted alpha to the new background, then blur the background enough that it visibly bleeds into what used to be solid subject. Take that blurred result and multiply it back through the original, non-inverted alpha so only a thin edge survives, then add that edge on top of your composite with a Merge node set to Additive or Screen.
The effect only reads as real when the blur amount matches how diffuse your actual background light is. A tight, sharp blur radius looks like a rim light from a music video. A wider, softer one reads as ambient bounce, which is what sells the composite in ordinary interview and product shots. Build the light wrap on its own branch of the node tree rather than folding it into your spill correction. When a client asks to soften or remove it, you want one clearly labeled Merge node to adjust, not a tangle of nodes doing two jobs at once.
DaVinci Resolve Green Screen Lighting Mistakes That Break the Key
No amount of Delta Keyer tweaking fixes footage that was lit wrong on set, and most of the shots that end up needing 40 minutes of Pre-Matte work trace back to 3 or 4 repeat problems. Uneven lighting across the screen is the most common one: one side reads a full stop brighter than the other, and a single Background Color sample can't cover both without a clean plate or heavy Pre-Matte range work. Wrinkles and creases in fabric screens create the same problem at a smaller scale, each fold casting its own tiny shadow and its own shade of green.
Subject-to-screen distance causes the second most common failure. Put your subject inside 6 feet of the screen and green spill lands on skin, hair and clothing hard enough that Fringe tab corrections start fighting real detail instead of just cleaning fringe pixels. Shadows are the third repeat offender, usually from lighting the subject and the screen with the same source instead of two separate setups. A shadow reads as a darker, different shade of green than the rest of the screen, and the Delta Keyer treats it as a separate color to key, not as "still background, just darker."
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.
DaVinci Resolve Delta Keyer Performance on Heavier Composites
A single Delta Keyer barely taxes anything. Stack 2 keyers for hard and soft edges, add a Clean Plate branch, a manual light wrap and a few color correction nodes, and a 4K shot can start dropping frames on a laptop GPU, especially with Fringe tab spill suppression running at full resolution while you're still adjusting sliders. Work at half or quarter viewer resolution while you dial in settings, then check the full resolution result before moving on. If you're keying regularly and want to know what hardware actually handles this without stuttering, the system requirements guide covers the GPU and RAM numbers that matter for Fusion specifically.
Once the key, spill and light wrap are locked, the composite goes back to the Edit page like any other clip. Export settings from there follow the same rules as anything else you deliver, covered in the export settings guide.
DaVinci Resolve Delta Keyer FAQ
What's the difference between the Delta Keyer and the Chroma Keyer in Fusion?
The Delta Keyer is a color difference keyer built specifically for blue and green screens, with a Pre-Matte tab, a Clean Plate input, a Tuning tab and a Fringe tab for spill suppression that the Chroma Keyer doesn't have. The Chroma Keyer works on any color, not just blue or green, which makes it the better tool for keying a colored wall or object rather than a dedicated screen.
Do I need a clean plate for every green screen shot?
No. A single Background Color sample handles a well lit, evenly colored screen without one. A clean plate earns its place when the screen itself has visible unevenness, wrinkles, reflections, gradients or shadowed patches, situations where one sampled color can't represent the whole background. Fine hair, smoke and motion blur are foreground problems. A clean plate won't fix those; the Matte and Fringe tabs handle that work after the clean plate normalizes the screen.
Why does my key still show green on hair after adjusting the Fringe tab?
Hair usually needs Restore Fringe on the Matte tab before Fringe tab settings do much good. If Threshold clipped the fine edge detail out of the alpha entirely, there's no semi-transparent pixel left for spill suppression to correct. Fix the matte first, then address remaining spill.
Can the Delta Keyer key a blue screen the same way it keys green?
Yes. Sample the blue screen color with the same Background Color eyedropper, and the Key, Pre-Matte, Matte and Fringe tabs work identically. Spill Method's Well Done and Burnt options are specifically tuned for blue screen spill rather than green.
Why does my Delta Keyer key show black splotches or noisy edges?
This usually points to compressed or noisy source footage, especially heavily compressed codecs at low bitrates. Try a higher Pre-Blur value, check that your footage isn't being processed in the wrong color space, and consider whether a second Delta Keyer node capturing just the soft edge detail, combined with your first key's solid matte, would separate the problem area from the rest of the shot.
Is the Delta Keyer available in the free version of DaVinci Resolve?
Yes. The Delta Keyer, Clean Plate node, garbage and solid mattes, and the core Fusion keying workflow are all part of the free version of DaVinci Resolve. DaVinci Resolve Studio adds other advanced effects, GPU and AI-assisted features, stereoscopic and high-end workflow tools depending on the version you're running, but the Delta Keyer itself isn't a reason most people need to upgrade. If you're deciding between versions for other reasons, the free versus Studio comparison breaks down the rest of the gap.
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.
