PIR Motion Detection Versus Continuous Recording

What PIR Actually Does

A passive infrared sensor watches for a change in heat across its field of view. Until it sees one, the camera is asleep and drawing almost nothing. The DVR-1080PDC draws 6 to 10mA at 3.7V when it is only running the clock, against 230mA when it is recording video and 1400mA when the infrared array is on. That ratio is the whole reason PIR exists.

Night Vision Smart Desk Clock Camera DVR-1080PDC shown from the front — Night Vision Smart Desk Clock Camera DVR-1080PDC · View specifications

What You Gain

Standby measured in weeks or months instead of hours. The DVR-1080PDC holds 15 to 20 days on two 2000mAh cells. The DVR-1080BKC book recorder holds a year on 8000mAh. The WF-720PFC photo frame holds 365 days on 10000mAh. None of those figures would be possible with the sensor running continuously.

Book Style PIR Standby Camera DVR-1080BKC shown from the front — Book Style PIR Standby Camera DVR-1080BKC · View specifications

What You Lose

The wake up is not instantaneous. The DVR-1080PDC takes 0.4 to 0.5 seconds to a still and 1 to 1.2 seconds to video. Anything that happens in that first second is not recorded. You also lose the continuity that makes footage easy to follow, because you end up with clips rather than a timeline.

Range And Angle Matter More Than People Expect

The PIR sensor has its own field of view, separate from the lens. On the DVR-1080PDC the PIR covers 100 degrees at 4 to 10 metres while the camera lens covers 65 degrees. Something can be in shot and not trigger, or trigger from outside the frame. Place the unit for the PIR range first, then check the framing.

When Continuous Recording Is The Right Call

Choose continuous when you need an unbroken record of a defined window rather than notice of events. A contractor visit, a trading day or an overnight shift. The DVR-1080DKC gives seven hours on 14500mAh and the DVR-1080PWC gives eight hours on 4200mAh, both without any network.