MotionBlur

Motion blur is the apparent streaking of rapidly moving objects within an image or frame, caused by the finite exposure time of a camera sensor or the way a rendering system samples motion over time. In photography and cinema, blur emerges when the shutter is open long enough for a moving point to traverse several pixels, producing a trail in the direction of motion. Blur can result from camera movement or from the movement of the subject, and its amount depends on exposure time, frame rate, speed, and direction of motion. Short shutter speeds reduce blur; longer exposures increase it. Rolling shutters can introduce additional distortions, such as skewing or jello-like effects, during fast pans.

In computer graphics and video work, motion blur is often simulated to increase realism and temporal continuity. Render-time methods use per-pixel motion information or sample positions across time to integrate light and color along a motion path, creating streaks that reflect velocity. Post-processing approaches can approximate this effect using velocity or motion vectors. The intensity and quality of digital motion blur are controlled by parameters such as shutter angle, exposure time, sampling density, and post-processing radius.

Motion blur serves to convey speed and fluidity, aiding perceptual continuity, but excess blur can reduce image clarity and legibility. It is commonly used intentionally in action scenes and cinematic sequences, while in some still photography or user interfaces it may be undesirable. In practice, motion blur considerations span camera technique, rendering settings, and real-time performance in games and video workflows.