CCTV Tips & Hacks: How Does Motion Detection Camera Work

CCTV Tips & Hacks: How Does Motion Detection Camera Work

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Artificial intelligence has changed the way CCTV used to work. You’ll find some security cameras promising to cut down false motion alerts by up to 99%. But then the question is, is that true? Will the system be something you can rely on all the time? And if Yes, how does a motion detection camera work to make sure you get to achieve exactly what you want?

Well, first things first, we now do have a motion sensor security camera that cuts down up to 99% of false alerts. And this means you’ll only get alerts or recordings that are relevant- i.e. when there’s a potential burglar or suspicious vehicle on your property.

What this also means is that you necessarily don’t have to keep your eyes glued to the monitor, phone, or computer all day. You can confidently continue with your daily routines, and the camera will notify you when there’s a pressing matter that requires your attention.

Similar to any other tech, motion detection has its drawbacks as well. And in this short guide, we’ve covered them all together to make sure you know exactly what you’re buying.

What Are Motion Detection Cameras?

 Motion detection cameras are CCTV systems that only record when they detect movements. They are pretty common nowadays, as even the continuous recording security camera can be adjusted to record by motions. And this applies to the wireless category, plus the wired systems with a DVR or NVR.

In the case of NVR and DVR, it’s usually more rewarding to just stick with the 24/7 recording mode. The recorder supports local storage enough to record continuously for up to two months, anyways.

Standalone battery-powered wireless security cameras are where the effectiveness of motion detection is more visible. Nearly all the brands in this category only support this recording mode since it saves on the battery charge. But the likes of Arlo Pro 4 and Ultra still have the option to record continuously when plugged into an AC outlet.

CCTV Tips & Hacks: How Does Motion Detection Camera Work
arlo camera

One thing to note is that the continuous video recording mode on the Arlo security camera requires a separate add-on monthly service. And this will cost at least $15/ month for just one camera since you’ll need to pair the CVR plan with an Arlo Secure service to make the most of it.

The Arlo Secure plan alone starts from $4.99/ camera (or $12.99/ unlimited devices), with 30 days of activity/ alert recording history. And here we can see the motion detection mode is more cost-effective than the continuous recording in the long run.

FYI: We’ve just used Arlo for reference here to support our point on the effectiveness of motion detection on a battery-powered wireless camera. Google Nest Cam is in a similar boat, with motion detection recording at $6 and $12/ month for 24/7 video history.

Benefit Of Using a Motion Detection Camera

Besides cost-effective cloud storage plans, the other benefits of a motion detection camera include:

  • Track your compound happenings: Once you’ve connected to the app, the motion detection camera will send you an alert whenever it detects an object. You won’t have to sit around your system all day, yet no one will enter or leave your property without you knowing.
  • Saves on the viewing time: when the camera only records motion detection events, it’s usually easier to pull up and playback the relevant footage clips. You won’t have to browse hours of history, as with the 24/7 continuous recording.
  • Saves on the local storage space: If you’re using a camera like Eufy or Wyze, the motion detection recording mode does maximize usage of local storage. It will take longer to fill the MicroSD card (or built-in Memory) than when recording in 24/7 continuous mode.
  • Improve store productivity: Some motion detection features can help improve the productivity of your business. A perfect example is “people counting” to track how many customers visit your store on particular days. Facial recognition and license plate recognition (LPR) detection features also allow you to whitelist or blacklist important objects
  • Get minimal false alerts: a smart motion detection camera makes sure you get to keep an eye on only what matters. The more advanced AI detection features available, the lesser false alerts you’ll have.

False alerts are the motion detection triggers that your camera picks, but are irrelevant. They can be motion alerts from things like leaves, twigs, insects, rain, and snow. Some cameras will even trigger events that aren’t exactly “physical” movements, such as a sudden change in the lighting condition.

When a camera has too many false alerts, it’s usually rather frustrating and annoying. You might even end up disabling the function, which kind of defeats the purpose of the system altogether.

But again, the number of false alerts you receive depends on the type of motion detection your camera has in place. And this now brings us to our main topic of the day:

How Does Security Camera Motion Detection Work?

 As we’ve just mentioned, the way security camera motion detection work varies from one brand to another. This is because it depends on the type of technology onboard, which can be either software-based or passive infrared (PIR).

Part 1: How Does Software-based Motion Detection Camera Work

A software-based (or computer vision) motion detection is a type of detection where a camera uses its software to register motion events. The detection software will analyze the frames of the live-streaming video, looking for a significant change in pixels.

Motion Detection setup

When an object enters the camera field of view, the detection software will register the change in pixels and triggers motion alerts. The number of pixels it analyzes per second will depend on the motion sensitivity setting. And considering we’re talking about a change in pixels of the captured video frames, it will work even behind glass. Hence, the reason many manufacturers utilize it for their indoor cameras.


Sadly, software-based motion detection isn’t exactly what we’d classify as smart AI. The camera has too many false alerts, as even things like leaves, twigs, insects, and shadows can register the change in pixels.

Part 2: How Does PIR Motion Detection Camera Work

In the case of Passive infrared (PIR) motion detection, the camera has a built-in sensor that tracks the movements of warm objects. The “objects” will require to emit sufficient heat to trigger this motion sensor. Thus, will have minimal false alerts since it can ignore events triggered by leaves, twigs, shadows, light changes, and even insects.

Thanks to its efficiency, CCTV makers are now going for PIR motion detection over the software-based model. It’s also power-efficient, which is why it’s more common in battery-powered security cameras than the wired-power options.

A perfect example is with Blink and Ring, whereby they use PIR motion detection for outdoor battery cameras. But the indoor cameras (which use wired power) from the brands utilize pixel-based motion detection technology.


A PIR-based motion detection camera usually uses most of its time in low-power mode. It also takes more to wake up and trigger alerts than pixel-based cameras. And for this reason, you may end up missing a crucial moment of events that happened fast.

Another thing, the PIR sensor can’t detect motions through the glass. So, you can’t use your camera behind a window to monitor the outdoors.

How to Setup Motion Detection

 The way you set up motion detection varies from one security camera to another. But for most of the security cameras, you just need to:

  1. Launch the mobile app you use to manage the camera
  2. Locate and tap on the settings menu
  3. Select the “motion detection settings”
  4. Tap on the Enable/ disable button

If your camera has been sending too many false alerts, adjust the motion sensitivity bar to the lowest setting possible. You can also set up motion detection zones, which allows the system to only focus on what matters while ignoring other regions.

Other smart motion detection features you can enable to cut down false alerts from your security camera include:

  • Person detection
  • Vehicle detection
  • Face detection
  • Facial recognition
  • Line crossing detection

Note: a PIR-based motion detection camera usually trigger events from people, animals, and vehicles. But there are advanced AI security cameras that you can set each of these modes individually.

Other features like license plate capture/ recognition are not exactly a must for home systems. But the feature can be handy in outdoor security camera systems for warehouses or any business building to track incoming/ outgoing vehicles.

Types of Security Cameras That Work with Motion Detection

 As mentioned earlier, all the types of security cameras in the market nowadays support motion detection. Some of the best brand options available include:

Security Camera BrandType of Security CameraMotion DetectionImage ResolutionAdvanced Detection
Ring Spotlight Cam BatteryRechargeable CameraPIR-based1080p FHDPerson detection
Blink Mini Plug-in CameraIndoor CameraSoftware/ Pixel-based1080p FHDN/A
Amcrest PoE PTZ CameraPTZ Camera  Software/ Pixel-based2K QHDFace/ human detection
GW Security IP CameraDomed CameraSoftware/ Pixel-based2K Super-HDFacial recognition
Lorex 4K@30fps CameraVarifocal CameraPIR-based4K Ultra-HDPerson/ vehicle detection
REOLINK 4K Outdoor CameraVandal-proof CameraPIR-based4K Ultra-HDPerson/ vehicle detection
Anran 2K 360-Degree CameraSolar-powered CameraPIR-based2K FHDN/A
Amcrest Panoramic CameraFisheye CameraPIR-based2K Super-HDPeople counting, Tripwire

In Conclusion

Motion detection is a crucial feature if you want to make the most of your security camera. We’ve seen it can save on your video playback time, cloud fees, local storage space, and battery charge on battery-powered systems.

Any time you’re buying a CCTV system, choose a brand with as many motion detection features as possible. It necessarily doesn’t have to be sophisticated AI, like facial recognition or people counting. The three basic modes (person/ pet/ vehicle detection) can suffice for most applications.

Even so, don’t forget motion detection is still technology like any other. You will have a few false alerts on even the smartest system out there- the 1% we always see in descriptions.