Method
Chooses the blur algorithm such as Multibox, Defocus or Soften.
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Blur & FocusIntermediate
VariBlur
Map-driven variable blur
Varies blur strength across the image from a selected channel or map, with multiple blur methods, quality, size and limit controls.
VariBlur
DaVinci Resolve · Fusion
Varies blur strength across the image from a selected channel or map, with multiple blur methods, quality, size and limit controls.
Overview
What VariBlur does
Varies blur strength across the image from a selected channel or map, with multiple blur methods, quality, size and limit controls.
Blur Channel chooses the map that varies blur across the frame, while Method selects the character of the blur. Alpha and Luma are useful for masks and depth-like control; None reduces the setup toward a conventional uniform blur.
Blur Size sets the base amount and Blur Limit caps extreme values from the control map. Build and inspect the map as a separate branch when possible—many VariBlur artifacts come from a noisy or hard-edged map rather than from the blur algorithm itself.
Mental model
Think of the selected channel as a blur-strength map: dark and bright values tell different parts of the image how much softness to receive.
Common uses
Blur a background from an alpha map
Create soft transitions across graphics
Build depth-like selective blur
Smooth only chosen luminance regions
Use procedural maps to animate blur
Flow anatomy
Inputs & outputs
The port structure shows how this node fits into a Fusion graph.
Image
Source image for the operation.
Effect Mask
Optional mask that limits where the node affects the image.
VariBlur
Fusion node
Output
The processed result from this node.
Inspector
Important parameters
Start with these controls before reaching for more complicated workarounds.
Quality
Controls processing quality versus speed.
Blur Channel
Selects Alpha, Luma, RGB channel or another source for the blur map.
Lock X/Y
Links horizontal and vertical blur.
Blur Size
Sets the maximum blur strength.
Blur Limit
Caps the blur produced by strong map values.
Practical setup
A reliable workflow
- 1
Connect the source and ensure a useful map/channel exists.
- 2
Choose the Blur Channel.
- 3
Select a blur Method.
- 4
Set Blur Size and cap it with Blur Limit.
- 5
Raise Quality only after the map and strength are working.
Typical node chain
Input→
VariBlur→
Output
Examples
Where this node fits in real work
Alpha-driven background blur
Use an alpha/matte to vary blur across the image.
MediaInMask / AlphaVariBlurMerge
Procedural softness
Drive blur from a noise/luma map.
FastNoiseVariBlurComposite
Troubleshooting
Common mistakes
Selecting a channel that contains no useful map
Using extreme Blur Size without a limit
Feeding a harsh map and getting abrupt blur transitions
Running high quality while still designing the effect
Production notes
Practical tips
Soften the map itself if transitions look stepped.
VariBlur is most useful when the map has deliberate gradients rather than binary values.
Related nodes