Speed ramps & slow motion

Park the playhead where the change should start and press Ramp to 25%. The clip eases into quarter speed over half a second and stays there. Ramp back to 100% eases out again. There is also 50%, 200%, and a ramp to a freeze frame. All of them are in the command palette, so you can just type “ramp”.

Slowing down automatically turns on Pixel Motion frame blending — 25% without it is the same frames held four times each, which reads as broken rather than as slow motion. (If you had deliberately set frame blending to Off, the command respects that and leaves it alone.)

What it works on

Anything with a source to retime: video, audio and pre-comps. Ramping a pre-comp retimes everything inside it.

Shapes and solids are excluded on purpose: a ramp retimes the footage, not the animation you put on top of it — the same separation After Effects makes. Your keyframes on the layer keep their own timing.

Why this beats keyframing “speed”

Speed is a rate; what the renderer needs is which source frame to show when, which is the mathematical integral of speed. This is why After Effects makes you shape a Time Remap graph by hand, and why that graph is famously awkward.

Premation lets you say it in the units you think in — “100% here, 25% there” — and computes the exact curve for you. The result is two keyframes with one derived Bézier, not ninety baked ones, and it is mathematically exact, not approximated. Open the graph editor and it is a curve you can still grab and reshape like any other.

Behaviour worth knowing

• Ramps chain. Ramping to 25% and later back to 100% starts the second ramp from quarter speed — it never snaps to full speed first.
• No jump cuts. Inserting a ramp mid-clip continues from the frame on screen; the footage never leaps back to the head of the clip.
• Earlier ramps survive later ones. Keyframes before the playhead are left alone.