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A Crash Course in Motion Sensor Cameras

Cameras with motion sensors overcome these issues by detecting motion and then notifying users, not only saving a great deal of time, but significantly improving the overall security of your property and the actual effectiveness of having a security system in the first place.

For those of you not in the know, fret not—we’ve covered all the essentials right here, so you’ll soon be a budding expert on motion activated security cameras.

What Is Motion Detection?

What Is a Motion Sensor Camera?

PIR, or ‘passive infrared’, is the sensor used by most motion activated security cameras. It detects infrared energy given off by living things, be it human or animal.

If there’s a rapid increase in infrared energy detected, the smart camera will start recording, or, if it’s a camera that alerts your phone, you may instead receive a push notification with the option to start livestreaming, or even the option to communicate in real-time with whoever’s on the other side of the lens.

The complexity of the motion sensing capabilities, and what the camera then does with it, depends entirely on the model. Some smart devices, for instance, can recognize contacts that you know via facial recognition technology, and some give you the option to ignore animals by only detecting heat above a certain weight. 

Credit: Security Camera King

Top 5 Best Wireless Motion Sensor Cameras

Arlo Pro 4 Spotlight

Best motion sensor camera outdoor 

Available from Arlo. From $199.99.

Arlo Pro 4 Spotlight
Image via Arlo

Google Nest Cam

Best motion activated camera for smart home

Available on Google Store. From $199.

 Google Nest Camera
Image via Google Store

Google’s flagship ‘nest’ product, the Nest Cam is a battery-operated wireless motion sensor camera. Chic and discreet, it’s suitable for use indoors and outdoors.

Google Nest Doorbell

Best motion sensor doorbell camera 

Available on Google Store. From $179.99.

Google Nest Doorbell camera
Image via Google

The Nest Doorbell is Google’s answer to video doorbells. The battery-operated version is wireless and attaches to either your door or the wall adjacent to it.

Much like the Nest Cam, by incorporating built-in intelligence, its motion sensing capabilities are quite advanced. It can tell the difference between people, packages, animals, and vehicles in real time, and send push notifications based on the information it gathers. ‘Nest Aware’ uses facial recognition to even notify you when a familiar face is at the door.

Two-way communication lets you communicate with whoever’s at the door, while the 3:4 ratio, displayed vertically, maximizes what you can see, from sky to ground.


Best motion sensor camera with night vision

Available to order via AlfredCamera. $39.99.

the front of AlfredCam
Image via AlfredCamera

AlfredCam marries quality and affordability, combining the great features found in the AlfredCamera app with new ones made possible only through hardware. 

Full color night vision is able to capture every detail in 1080p HD even in environments with virtually no light.

When Alfred detects something unusual, it will instantly notify you, and allow you to use two-way communication wherever you are via the app. Other features like night vision make it a totally robust means of securing your property.

Zmodo Pivot

Available from Zmodo. From $59.99

the Zmodo Pivot 1080p Wireless Security Camera.
Image via Zmodo

If an old smartphone isn’t lying around the house, you don’t have to break the bank to get a decent wireless motion sensor camera. Zmodo offers a robust yet inexpensive option for well under a hundred dollars.

The Zmodo Pivot records in up to 1080p, using a wide-angle camera to gain maximum visibility. As the name suggests, Zmodo can ‘pivot’ in 360°, so that when significant motion is detected, you can enable a full sweep of the room recorded in a short clip. Push notifications sent to your phone will then let you see the sweep of the room.

It also happens to provide temperature and humidity reading, and act as a Bluetooth speaker, allowing for two-way communication. No doubt, you’ll be getting bang for your buck!

Credit: Techs You Can’t Live Without

Can You Turn Your Phone Into a Motion Sensor Camera?

With the overlap between camera technology and smartphones, it’s hardly any wonder that it’s now possible to have your phone act as a fully functional wireless motion sensor camera.

Aside from the various cameras that alert your phone when it detects unusual activity that are available on the market, there are also emerging options for motion activated camera apps that require no additional hardware to function.

‘Before AlfredCamera was founded, Alex lived in a humble apartment. He was just 20 years old when he experienced his first burglary … That was when he came up with the idea of portable, inexpensive security cameras.’ 

Alex Song, Founder and CEO of AlfredCamera


What is a PIR sensor?

A PIR sensor (passive infrared sensor) detects infrared energy given off in the scene it observes. Everything that emits heat also emits infrared energy, but infrared is invisible to the human eye. The PIR observes the shifting wavelengths. This information can then be processed to reveal information about movement, depth, size, and heat.

How much does a motion activated camera cost?

Motion activated cameras are generally no more or less expensive than any other IP camera on the market, owing to the fact that it is now a more commonplace feature. AlfredCam, one of the best options on our list, retails for $39.99, making it by far the most affordable option.

Do motion sensors work in the dark?

How far can security cameras detect motion?

Generally, security cameras detect motion somewhere in the vicinity of 15 to 25 feet. AlfredCam is able to detect motion up to 32 feet in daylight, and up to 22 feet in night vision mode.

What do motion sensors see?

In the context of cameras, motion sensors see infrared. A PIR (passive infrared sensor) is the type of sensor that detects general movement, but an imaging sensor is needed as well in order to gauge information about who, or what, moved, and these sensors are in all cameras. This compares sequential images from the footage, frame by frame, to determine information based on changes to the pixels.

Do motion sensor cameras record all the time?

Motion sensor cameras do not record continuously. While they are ‘observing’ all the time, the advantage of a motion activated security camera is that it can be configured to only record and save footage when the sensor detects movement, thereby saving memory. Many cameras also allow for certain parameters to be changed, like only activating when objects of certain weights, sizes, or temperatures are detected.

Why is motion detection not working?

Issues with motion detection could be down to a number of different things, including incorrect settings/setup, lights or other obstructions confusing the sensor, or even a damaged circuit board.

Can a mouse trigger a motion sensor?

A mouse is unlikely to trigger a security camera motion sensor, but in theory, it could. The factory settings of most commercial security cameras with motion sensors would purposely have the sensor ignore something so small. It would trigger it if it came very close to the lens.


Improving the safety of your property isn’t just a matter of installing any old camera. We live busy lives—we need technology that’s going to actually be useful to us, and that requires convenience. With that in mind, motion detection is a vital feature you’ll need to get the most out of your security setup.

Motion detection means that you can go about your life without having to think twice about sifting through potentially hours of security footage. Your device will let you know when it detects something, thereby streamlining the process and significantly improving the security of your property.