Motion blur

Fast movement in a video with no blur looks like a slideshow of sharp frames. A little blur is what makes it read as movement. Cilevi has three separate settings for it.

The pointer

On a clip's Cursor tab, Motion blur smears the pointer along its path while it is travelling quickly. Subtle, and worth having on.

The screen

With nothing selected, the Motion tab has two more: Screen zooming in and Screen moving. These blur the picture itself while the zoom camera is changing size or position.

This is the setting that makes automatic zoom feel cinematic instead of mechanical. Without it, a zoom is a sequence of perfectly sharp frames at slightly different scales, which the eye reads as a jump rather than a move.

Why the preview looks different

The preview shows screen blur on a paused frame, but skips it during playback. It is expensive to compute, and computing it would cost the preview its smoothness, which is a worse trade: a stuttering preview tells you nothing about the finished video.

The export always has it. If you want to check what it will look like before committing, pause on a frame in the middle of a zoom.