Motion-to-Photon Latency

What is Motion-to-Photon Latency?

Motion-to-Photon Latency measures the total delay between a user's physical movement and when that movement is visually reflected in a display, with lower values (ideally under 20ms) being critical for preventing discomfort in immersive applications.

This comprehensive performance metric encompasses the entire pipeline from physical motion detection through rendering to display refreshing, making it the most meaningful measure of system responsiveness in immersive contexts.

What is the breakdown of the Motion-to-Photon Latency pipeline?

The complete latency chain includes tracking system delay, data transmission time, application processing, render pipeline execution, display refresh characteristics, and any additional processing like reprojection or distortion correction.

High motion-to-photon latency creates a disconnect between vestibular sensations (what users physically feel) and visual feedback, which frequently triggers simulation sickness, particularly during rapid head movements. This physiological mismatch explains why even high frame rate applications can cause discomfort if tracking data is delayed or processing introduces bottlenecks.

Why is Motion-to-Photon Latency important to solve?

The challenge of minimizing this latency creates significant obstacles for cloud-based rendering solutions in immersive applications, as network transmission inherently adds delay that can exceed physiological comfort thresholds regardless of server-side performance.