What Reaction Threshold means
Motion Strength is the share of sampled frame areas that changed. A lower Reaction Threshold reacts more readily; a higher one filters more small changes. Lighting changes, windows, screens, moving plants, pets, and camera shake can all create frame differences.
Use this as a starting point
This test is a local calibration, not a guarantee or an objectively optimal setting. Create representative movement during the test, then repeat it under the lighting conditions in which you plan to monitor. If the scene stays active, stabilise the camera or use an Ignore zone around changing areas. Use a Watch zone when only one area matters.
What happens when you apply it
The suggested threshold is placed in a small, one-time session value for this browser and then applied by the Motion Detector. It contains only the clamped number and version metadata. It never starts the camera. See the false-alarm guide for a local troubleshooting sequence.