By default, captured face frames are saved based on the quality level: each subsequent face image is compared with the previous image. If the quality level is equal to or higher than the previous one, then the new frame is saved. If not, the frame is not saved. This setting corresponds to the checked Best angle only checkbox on the Advanced settings tab of the Face Recognition Server object (1).

If it is necessary to save all frames of captured faces regardless of quality, then uncheck the Best angle only checkbox and click the Apply button (2) to save the settings.