Workflow guide
Slow motion that hits exactly on the beat
Speed ramping turns flat action into cinema: full speed into the moment, floating slow motion through it, snap back out. The difference between smooth and seasick is frame rate, ramp placement, and curve shape. This guide covers all three.
From the Mellius product team · Updated September 28, 2026
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- ›Remove all silent parts
- ›Add bold kinetic captions
- ›Only have Bill Ackman speaking
- ›Cut to highlights only
- ›Add cinematic transitions
- ›Match cuts to the beat
The short answer
Shoot at sixty to one hundred twenty frames per second with a shutter near one over twice the frame rate, mark ramp points on action beats, ease into forty to fifty percent speed through the peak, smooth the curve handles, and add subtle sound design so the ramp feels intentional.
Slow sections stay smooth
High frame-rate capture means real frames in slow motion instead of stuttering interpolated ones.
Ramps land on beats
Speed changes trigger on hits, cuts, or music accents so the effect feels motivated.
Curves ease, never snap
Gradual bezier transitions keep viewers oriented instead of lurching between speeds.
Capture frames the ramp can spend
Shoot sixty frames per second minimum for gentle ramps and one hundred twenty for deep slow motion, keeping the shutter near one over twice the frame rate for natural motion blur. Lock exposure and white balance before the take, because ramping across flicker or shifting color makes the effect look broken. Plan the peak moment in advance — the jump, the splash, the turn — so the camera move already favors it instead of discovering slow motion in footage shot at twenty-four frames.
Stabilize before retiming. Warp stabilizers and speed changes multiply each other's artifacts, so stabilize the full-speed clip first, nest or compound it, then retime the stable result. Common pitfall: ramping 24 fps footage down to forty percent and hoping optical flow invents the missing frames. Optical flow rescues small gaps but smears hands, balls, and water into jelly on big slowdowns.
- Shoot 60 fps minimum, 120 fps for deep slow motion.
- Hold the 180-degree shutter rule for natural blur.
- Stabilize first, then retime the nested clip.
Shape ramps that feel inevitable
Place ramp keyframes on action beats: start easing just before contact, hold the slowest speed through the peak two to ten frames, then accelerate out on the reaction. Shape the curve with eased bezier handles rather than linear segments — roughly a quarter to half second ease on each side keeps the transition readable. Hold forty to fifty percent speed for most ramps; slower suits only true peak moments, since long super-slow stretches drain momentum.
Sell the ramp with sound: dip the production audio into the slow section, layer a soft whoosh across the transition, and land a subtle hit as speed returns. Preview at full resolution, because retiming artifacts hide in proxy playback and ambush the export. In Mellius you can ask for a speed ramp into slow motion across a named moment and fine-tune the curve on the timeline with undo intact.
- Ease in before contact, hold through the peak, accelerate out.
- Favor forty to fifty percent speed except for peak moments.
- Design the sound so each ramp feels motivated.
Compare the workflows
| Method | Best fit | Trade-off |
|---|---|---|
| High frame-rate slow motion | Smoothest slow sections | Needs more light and storage |
| Speed ramp with curve | Cinematic transitions between speeds | Demands careful keyframe shaping |
| Constant slow motion | Simple dreamy or analytical passages | No energy contrast without ramping |
A practical sequence
Put it into practice
- 01
Shoot for slow motion
Record at sixty to one hundred twenty frames per second with locked exposure and the 180-degree shutter.
- 02
Place and shape the ramp
Mark keyframes on action beats, ease through forty to fifty percent speed, and smooth the handles.
- 03
Finish with sound
Dip production audio, add transition sound design, and preview at full resolution before export.
Frequently asked questions
What frame rate do I need for smooth slow motion?
Sixty frames per second covers gentle slow motion down to about fifty percent on a 30 fps timeline. One hundred twenty frames per second covers deep slow motion to twenty-five percent cleanly. Below those ratios the software must invent frames, which causes smearing on fast detail.
Why does my speed ramp look jerky?
Three usual suspects: linear keyframes that snap between speeds, footage shot at too low a frame rate, and retiming before stabilizing. Convert keyframes to eased beziers, shoot higher frame rates next time, and stabilize the clip before applying the ramp.
Should I use optical flow for speed ramps?
Use it sparingly as a rescue tool for small gaps, not as the foundation of deep slow motion. Optical flow smooths mild retimes well but warps hands, faces, and water on big slowdowns. Real high frame-rate frames always beat synthesized ones for hero moments.
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Primary sources
Product capabilities change. These official references support the comparisons above.
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