RESOLVE 21 · TEMPORAL MOTION ESTIMATION
Motion Blur.
Track the motion.
Then decide how the shutter should feel.
Resolve FX Motion Blur is a Studio-only temporal effect, not a static smear. It analyzes movement between frames, works inside a chosen Motion Range, synthesizes a temporal streak, lets you bias that streak toward previous/both/next frames, and only then offers Granularity and Global Blend for refinement. The important skill is diagnosing a bad motion model before increasing blur strength.
Mo. Est. Type + Motion Range
Amount + Direction + Granularity
Playback · 100% · Encode
Use the lab to force a range mismatch and an occlusion failure. The useful lesson is not the exact synthetic pixels; it is the order of diagnosis: estimator and range first, blur amount second, Blend last.
Teaching proxy, not Resolve rendering. The animation deliberately simplifies optical-flow/motion-estimation behavior to make range mismatch, direction, sampling density, occlusion risk and final blend understandable. It does not reproduce Blackmagic vector fields, kernels, color management, renderer precision or exact performance.
Six native Resolve interface views + an explicitly synthetic temporal teaching proxy
6 native views · 6 controls · 4 exercises01WHAT THE EFFECT IS ACTUALLY SOLVING
Motion Blur is a chain of temporal decisions, not one strength slider.
A clean result requires a believable motion interpretation before styling. That is why the page separates analysis, displacement scale, temporal direction, sampling, and final mix.
This is temporal reconstruction, not directional blur
Motion Blur is a Studio-only temporal Resolve FX. It uses optical-flow-based motion estimation to analyze movement between frames and selectively add artificial blur according to the speed and direction of moving elements. The result is therefore not defined only by visible streak length: Resolve first has to map motion convincingly enough. On difficult occlusions, crossings, hair, limbs, and fine contrast detail, motion estimation can matter more than the amount itself.
Range must match the motion
Motion Range is not a quality preset. The manual defines it as the control that determines what speed of motion to consider when defining regions being blurred. Small, Medium, and Large should be chosen for the dynamics of the shot, not by assuming that bigger means better. A range that is too small may fail to cover fast motion; an unnecessarily large range does not automatically create extra quality.
Direction sets temporal geometry
Blur Direction decides where the streak sits relative to the current object position: behind it, symmetrically, or toward the next position. In footage this changes the perceived shutter feel; in titles and motion graphics it also changes the graphic sense of movement.
Temporal artifacts are often invisible on a chosen still frame. Ghost edges, tearing, vector flips, and unstable occlusions reveal themselves over time. Watch several seconds at real speed, then inspect difficult edges at 100% and a representative delivery encode.
02SIX CONTROLS · SIX DIFFERENT JOBS
Read the native panel as a dependency chain.
The screenshots below come from the project archive. Dropdown captures prove exact option names; the guide does not turn the captured 50.0 / 10 / 1.000 values into presets.
MOTION MODEL
Make the motion model believable before styling the blur
- Mo. Est. Type
Selects the motion-estimation mode. The native menu contains None, Faster, and Better. Blackmagic describes Better as more accurate pixel mapping at the expense of more processing, while Faster is more approximate and less processor intensive. None is visible in the native dropdown and is useful as a diagnostic comparison state.
CheckWatch independently moving subjects, crossings, hands, hair, fine contrast edges, and camera motion. If the trail fails only locally, the cause is more likely here or in Motion Range than in Blend.
- Motion Range
Determines what speed of motion to consider when defining regions being blurred. The native menu offers Small, Medium, and Large. It is neither the blur amount nor a quality level; the range should match the dynamics of the shot.
CheckIf a fast subject loses its trail or matching becomes incorrect, test a more suitable range before changing Motion Blur amount. Do not choose Large for gentle movement simply because it sounds “higher quality.”
- Motion Blur
The main effect amount, ranging from 0 to 100: 0 applies no Motion Blur and 100 is the maximum parameter value. The saved screenshot shows 50.0; that is a captured interface state, not a recommended preset.
CheckIncrease it until the intended shutter feel is reached, then stop before excessive smearing, double edges, or the impression that blur is hiding a poor vector field.
TEMPORAL SHAPE
After analysis, shape the streak in time
- Blur Direction
Sets the temporal bias: From Previous Frame, Both Directions, or Towards Next Frame. Both Directions is a neutral starting point; the one-sided modes emphasize the previous or next position relative to the current frame.
CheckCheck direction on titles, bright points, hands, and subjects crossing contrasty backgrounds. The wrong orientation can feel like the image is lagging behind or leading the motion unnaturally.
- Granularity
The manual defines Granularity as controlling how much detail is added to the blur. In practice it makes sense to adjust it after estimator, range, amount, and direction: it refines an already chosen blur result but does not replace correct motion estimation.
CheckCompare streak smoothness, fine moving edges, and render cost. If the real problem is a wrong vector or occlusion, granularity usually only renders the wrong solution in more detail.
FINAL MIX
Use Global Blend only after the temporal solution is correct
- Global Blend
Mixes the computed Motion Blur result with the source image. The saved Inspector shows 1.000 for the full effect state of that capture; reducing Blend restores part of the source without changing the motion model.
CheckUse it for final integration. If Blend has to be reduced dramatically just to hide tearing or ghosting, return to Mo. Est. Type, Motion Range, and Blur Direction.
One practical rule keeps this panel sane: if the streak geometry is wrong, do not touch Global Blend yet. Fix estimator, Motion Range, amount and direction first. Blend is a finishing control, not a diagnostic repair.
03A REPEATABLE TEMPORAL WORKFLOW
Source → estimate → range → amount → direction → QC.
This order prevents a familiar mistake: trying to hide an incorrect motion model by lowering Blend or adding even more blur.
Identify the motion problem
Decide whether the shot needs believable shutter extension, a stylized speed accent, or no temporal reconstruction at all. Finish retiming first so Motion Blur is not asked to hide retime artifacts.
This is an editorial decision path, not Blackmagic’s published internal processing graph. It deliberately separates motion analysis, range, blur amount, temporal direction and final QC so Global Blend does not become a shortcut for hiding a bad motion model.
Related reference: Directional Blur ↗ · Motion Trails ↗ · Frame Replacer ↗
04FOUR MOTION STRESS TESTS
A pan, a fast subject, a title and a speed ramp fail for different reasons.
Treat these as diagnostic procedures rather than presets. The same 50.0 value can be acceptable on one shot and completely wrong on another because displacement, occlusion and cadence differ.
Fast whip pan
Restore a believable shutter streak during a pan without doubled verticals or dirty edges.
- 01
Start with Faster and Medium, then play the section at real speed.
- 02
If the pan is large and edges are lost, test Large before increasing the amount.
- 03
Compare Both Directions against a one-sided mode; for natural footage, start with Both Directions.
- 04
At 100%, inspect door frames, lights, text, and other hard vertical edges.
- 05
Only after the vector behavior is clean should you dose the result with Global Blend.
Fast moving subject
Add speed and shutter feel without turning limbs and occlusion boundaries into ghost copies.
- 01
Choose a representative section where the subject crosses a contrasty background.
- 02
Compare Faster and Better specifically at the crossing, not on an easy frame.
- 03
Match Motion Range to the real displacement between frames.
- 04
Raise Motion Blur to the intended sense of speed while watching for double contours.
- 05
Check where the subject enters and leaves frame; occlusion failures reveal themselves there first.
Title or motion graphic
Create a directional temporal streak that supports the trajectory instead of merely softening the text.
- 01
For graphics, first decide whether the trail should remain behind the motion or extend symmetrically.
- 02
Choose Blur Direction deliberately; here temporal bias often matters more than realism.
- 03
Keep Motion Range only as large as required by the actual displacement.
- 04
Use Granularity to smooth a longer trail while preserving letter readability.
- 05
Compare against Directional Blur if temporal reconstruction is unnecessary and a clean 2D smear is sufficient.
Speed-ramp accent
Tie a changing speed feel to synthetic shutter extension without temporal wobble.
- 01
Finish the retime first and confirm the retime process itself is not introducing warping.
- 02
Add Motion Blur only after the timing is approved.
- 03
At the fastest sections, compare Medium/Large and Better.
- 04
Do not hide retime artifacts with stronger blur; identify which stage is producing the failure.
- 05
Before delivery, inspect speed transitions frame-by-frame and in playback.
05CHOOSE THE RIGHT MOTION TOOL
Temporal reconstruction, temporal echoes and 2D smear are not interchangeable.
Choose the algorithm by the visual problem. A tool that is simpler but matches the job is often cleaner than forcing motion estimation into every moving graphic.
| FX | When it fits |
|---|---|
| Motion Blur | Choose it for motion-estimation-based blur tied to movement between frames. |
| Motion Trails ↗ | Choose it when visible temporal echoes/trails and a more graphic accumulation of motion are the goal. |
| Directional Blur ↗ | Choose it for a simple 2D smear along a chosen angle without inter-frame motion analysis. |
| Smear ↗ | Choose it for stylized motion deformation or stretching rather than a believable shutter response. |
06READ THE FAILURE BEFORE MOVING A SLIDER
Broken trails, ghost edges and wrong timing point to different controls.
Temporal work gets faster when you identify whether the failure is search range, motion matching, amount, direction, sampling, or downstream compression.
01The trail breaks on a fast subject+
Likely cause: Motion Range is too small or the estimator is failing on the real displacement.
Fix: First choose a larger Motion Range that matches the motion, then compare Faster and Better on the failing section.
02A double edge or ghost copy appears+
Likely cause: Difficult occlusion/matching, excessive amount, or an unsuitable temporal direction.
Fix: Check vector behavior with a lower Motion Blur value, compare Better, and test Blur Direction. Do not treat the error with Blend alone.
03The frame looks like ordinary mush+
Likely cause: The amount is too high or the motion model is not producing convincing directional structure.
Fix: Reduce Motion Blur, re-check range/estimator, and compare against Directional Blur; a temporal FX may not be necessary for this shot.
04The streak feels temporally backwards+
Likely cause: Blur Direction does not match the intended temporal bias.
Fix: Compare From Previous Frame, Both Directions, and Towards Next Frame on the same contrasty moving edge.
05Raising Granularity does not fix the artifact+
Likely cause: The problem is in motion estimation/range/occlusion rather than blur sampling density.
Fix: Return Granularity to a sensible working value and fix the motion model first.
06The Viewer looks fine but the encode shimmers or doubles+
Likely cause: A temporal artifact is being emphasized by scaling, compression, or real playback cadence.
Fix: Check 100%/1:1, real-time playback, and a short encode in the target codec/size. If needed, reduce the amount after correcting estimator/range.
07BEFORE DELIVERY
Approve the vector behavior, the shutter feel and the encoded motion.
A still-frame approval is not enough for a temporal effect. The checklist keeps the decision tied to playback and the actual deliverable.
08FAQ
Practical Motion Blur questions.
How is Motion Blur different from Directional Blur?
Motion Blur uses inter-frame motion estimation and builds its streak from movement over time. Directional Blur simply smears the image along a chosen direction and does not need to understand the subject’s real trajectory.
When should I use Faster versus Better?
Faster is practical for preview and setup. Better is worth comparing on difficult moving edges, occlusions, and final quality. It does not need to be selected automatically for every shot.
Is Large Motion Range always higher quality?
No. It describes expected motion scale, not a quality level. Choose the smallest range that is sufficient for the real displacement.
Why can’t I approve the effect on one frame?
Because tearing, vector flips, ghosting, and occlusion artifacts exist over time. A single good-looking frame can completely hide temporal instability.
Which Blur Direction is the most neutral?
Both Directions is usually a neutral starting point. The one-sided modes are useful when the previous or next position should be emphasized to change the temporal feel.
Is Granularity a quality control?
It is better understood as the sampling/detail of the trail construction. It can improve the smoothness of motion description, but it cannot fix an incorrect motion vector or replace the correct Motion Range.
Can I just reduce Global Blend when artifacts appear?
You can reduce visibility, but that does not fix the cause. If the artifact comes from estimator/range/direction, correct the temporal model first and use Blend only as the final dosage control.
Is Motion Blur available in the free edition of Resolve?
No. In the current Resolve 21 manual, Resolve FX Motion Blur is marked Studio Version Only.
Sources and boundaries
Control names and interface states are anchored by six native Resolve screenshots stored in this project and the current Blackmagic Resolve 21 documentation. The live hero is an editorial teaching proxy: it intentionally exaggerates range mismatch and occlusion failure and does not claim to reproduce Blackmagic optical-flow vectors, kernels, hidden heuristics, color management or renderer precision.
Verify exact performance, Studio availability, UI placement and behavior in the Resolve build you use. This page documents the visible controls and a repeatable evaluation workflow; it does not reverse-engineer the OFX implementation.