Definition
What is motion blur in video?
Motion blur is the blur recorded when a subject or camera moves while a video frame is being exposed. Its amount is primarily controlled by exposure time relative to motion and frame rate.
At ordinary cinema frame rates, a moderate amount of motion blur helps successive frames blend into motion. A longer shutter exposure increases the blur, while a shorter one freezes motion more sharply and can make playback appear harsh or staccato.
Motion blur is not the same as out-of-focus blur or camera shake. It can be reduced with a faster shutter or added later with effects, but post-generated blur may not perfectly reproduce the occlusions and detail of a real exposure. It should be chosen for the action and intended feeling.
Example in the edit
A fast pan at 24 fps and a 180-degree shutter produces a natural streak across background lights; shortening the shutter makes the same pan show sharper individual details.
Why editors use it
Motion blur strongly affects how movement feels, and inconsistent blur between shots can be as distracting as an inconsistent frame rate.
Quick answers
Frequently asked questions about Motion blur
How can you reduce motion blur?
Use a shorter exposure time or smaller shutter angle, while compensating for the lost light with aperture, ISO, ND changes, or lighting as appropriate.
Is motion blur always desirable?
No. It should suit the motion and style; sports analysis may need crisp frames, while narrative motion often benefits from a conventional amount of blur.
Can stabilization remove motion blur?
No. Stabilization can reduce camera movement, but it cannot restore detail already blurred during exposure.