Interpolated slow motion (optical flow)
Artificial slow motion that estimates movement and invents the missing in-between frames instead of repeating recorded ones.
See it
What it is
Interpolated slow motion creates frames the camera never recorded. Optical flow estimates how pixels move between two real frames, then warps those frames to draw the missing moments. It looks smoother than repeating frames and sharper than dissolving between them. After Effects calls its version Pixel Motion, RE:Vision Effects sells Twixtor as the dedicated plugin for the same job, and DaVinci Resolve's Speed Warp runs the estimate through its Neural Engine.
Reach for it when the source frame rate is too low for the slowdown you need, especially for a brief product move, gesture, or speed ramp. Clean movement against a plain background gives the estimator its best chance.
Gotcha: optical flow cannot see behind objects. Crossing limbs, hair, water, smoke, flashing lights, and objects entering the frame can produce rubbery edges or fused shapes. Inspect every invented frame. When a section breaks, shorten the slowdown, cut around it, or switch that section to frame blending.
Ask AI for it
Slow this 24fps clip to 40 percent in Adobe After Effects, enable Frame Blending, and set the layer to Pixel Motion rather than Frame Mix. Keep the slowdown only around the key action, inspect the result frame by frame for warped hands, doubled edges, and tearing at occlusions, and use Frame Mix on any short section Pixel Motion cannot solve cleanly. Do not describe the invented frames as true high-frame-rate footage.