Even with the best security system on the market, there are glitches and problems that can occur. One of the issues is a motion detector being triggered by more than just motion. Sometimes these sensors seem to alarm when there’s nothing there, or they turn on a light or other device — such as a camera — that they’re designed to turn on when they detect motion. So, what’s with the motion detector coming on without motion? What is it “seeing” that’s really not there? There are several explanations, and most of them are easily adjusted for.


First, it’s important for a homeowner to consider that light may be triggering the detector. Since it senses patterns of light and shadow to determine whether there’s movement in the area it’s covering, it makes sens that those changing light patterns would be enough to set off the detector and the other devices it’s tied to. When a homeowner’s trying to figure out what’s setting off the motion sensor light with camera, they should consider:

  • dappled patterns, such as sunlight through moving tree leaves, can set off motion detectors
  • enough dust motes being caught in a sunbeam can be seen as motion
  • slower moving light changes, such as the sun moving across the sky, aren’t enough to trigger sensors in most cases

That’s why where a motion detector is placed is so very important, because it may end up being triggered by something that doesn’t really count as motion at all. That can lead to a lot of false alarms and can go a long way toward making a homeowner nervous that something or someone may be moving around their property or getting in their house.

Motion Detectors See More Than Just Movement

A motion detector sees movement, but it relies on what that movement is doing. Namely, changing the light or shadow levels as it goes by. Because that’s how these sensors work, it’s possible that the way a tree is blowing in the wind and casting patterns on the carpet can be enough to set off a motion detector.

That can be frustrating, but the solution is usually just to move the motion detector to another location where it’s not picking up on that pattern.

If the sensor is needed in that spot the sensitivity may need to be turned down. Additionally, the homeowner could get heavier blinds or curtains that would block that light pattern from being so obvious. That could reduce false alarms, and give a homeowner more peace of mind.

How to Adjust Lighting to Reduce False Alarms

With a security system that includes motion sensor light with camera, adjusting lighting to reduce false alarms matters. That can be done in a number of ways that don’t involve curtains or blinds. Removing objects that are reflecting light or causing patterns is one of the ways to do that, such as moving a tree whose leaves are creating issues. Another way a homeowner can adjust light is to have it be brighter in the home during the day, so there’s less of a contrast between inside and outside light sources.

Let the Security Company Help Address the Issue

For homeowners that use a security company, the company may be able to help them adjust their lighting and motion detectors so that false alarms are almost always a thing of the past. There’s always the potential for a glitch to occur, and sometimes the sensor may still trigger, but it should be a lot less likely to happen after adjustments have been made.

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