Symptom
Moving objects that are too small or have insufficient contrast with their background may not be easily distinguishable for motion detection recording, causing some events to go undetected and therefore unrecorded.
Solution
To resolve the above-mentioned symptom, disable the Noise Tolerance function and set the region sensitivity to 10.
1. Under System Configure (Home > Toolbar > Configure), select Record Setting.
2. In the Record Setting dialog box, select one camera and click the button.
3. Set the region sensitivity to 10, unselect Noise Tolerance, and click OK.
Since objects that are too small or have insufficient contrast might be detected as noise and be ignored with noise tolerance function enabled.