Why does my security camera keep alerting on nothing?

A camera that cries wolf gets muted, and a muted camera is no camera at all. Nuisance alerts are worth fixing properly rather than tolerating, and nearly all of them come from a short list of physical causes rather than from a faulty device.

What you'll need

• A soft cloth and warm soapy water
• A stepladder
• Silicone-based spider repellent or a plain water spray (optional)

Step by step

1. Look at the clips before changing any settings.The recording almost always shows the cause: a web strand across the lens, a moth, a branch, a car's headlights sweeping the wall. Diagnose from the evidence rather than by guessing.
2. Clean the lens, the housing and the IR window.Warm soapy water and a soft cloth. Webs are the single biggest cause of night alerts, because a strand a centimetre from the lens is enormous in frame and lit brilliantly by the infrared.
3. Deal with what attracts insects to the camera.The IR illuminator draws moths, which draw spiders. Moving the camera away from the wall, fitting a hood, or wiping the housing with a silicone spray monthly all reduce it. Do not spray insecticide onto or near the lens.
4. Draw motion zones tightly.Cover the path and the door, and exclude the road, the pavement, trees and the neighbour's washing line. This also reduces your data-protection footprint, so it is worth doing twice over.
5. Turn on person or vehicle detection if the camera has it.On-device or cloud object detection cuts nuisance alerts dramatically compared with raw pixel-change motion. It is often the single setting that fixes the problem.
6. Lower sensitivity in stages.Reduce one step and live with it for two days. Dropping straight to minimum usually means missing what you care about, and you will not know which step was enough.
7. Get light sources out of the frame.A security floodlight, a street lamp or car headlights sweeping through the picture look exactly like motion. Re-aim the camera, or re-aim the light.
8. Watch for sunlight and shadows through the day.A shadow tracking across a wall in the afternoon, or sun glinting off a car, triggers repeatedly at the same time each day. A predictable time of day is the giveaway.
9. Cut back what moves.A branch or a tall shrub in frame will trigger on every breeze. Pruning it fixes the alerts and improves the view at the same time.
10. Set a schedule if the problem is time-bound.Alerts only when the house is empty or overnight, rather than all day. Recording can continue while notifications do not.

Tips

• Alerts you actually read are worth more than alerts you receive. Tune until you get a handful a day, not dozens.
• Rain and snow at night light up like static in infrared. A hood or an overhang helps more than any setting.
• If two cameras cover the same space, turn detection off on one. Duplicate alerts are the fastest route to muting both.

Common mistakes

• Turning notifications off instead of tuning them — The camera then only helps after the fact. Fixing the cause keeps the alerting useful, which is most of the reason to have it.
• Spraying insecticide on the camera — It damages plastic housings and lens coatings, wastes chemical outdoors, and lasts days. Physical cleaning and a hood work better and keep working.

If it doesn't work

Questions people ask