How Do Video Doorbells Detect Motion and How Do They Work?

As more and more Australians seek to increase the security of their homes, there has been an explosion in the popularity and installation of video doorbells. These devices even come with motion detectors, which have a significant impact on their effectiveness.

This article digs deeper into video doorbells, how they work and just why motion detection technology is so important.

Understanding motion detection in video doorbells

While some doorbell cameras record all the time, most models only record when they detect motion in the motion detection zone. The camera will record until no further motion is detected.

The video doorbell will even send a notification to your phone so you can watch the video and determine the source of the motion. This allows you to make a call on whether the motion detected is a threat or not.

Some models even start recording just prior to the event that triggered it. What this means is that if someone came up to your porch and stole something, you’ll be able to see which direction they approached from.

Types of motion detection technologies in video doorbells

This section takes a closer look at the different types of motion detection technology integrated into video doorbells.

Passive Infrared (PIR) Sensors

Passive Infrared Sensors are heat motion sensors. They detect changes in heat in the detection zone. As people emit more heat than the surrounding environment, the sensor picks up on this heat when someone enters the zone. If the sensor detects a temperature rise, it sends out an alert. The doorbell needs to be positioned correctly, otherwise the sensor may detect the heat of passing vehicles if it’s placed too high. Talk to your security company professional about the correct placement of the doorbell and PIR sensor for best results.

Camera-based motion detection

With a video doorbell equipped with a high-resolution camera, motion is more readily and accurately detected when someone enters the detection zone. You don’t need to wait for someone to ring the doorbell for the camera to be triggered and start recording. Ideally, opt for camera-based motion detection with night vision, as this enables the camera to be more effective after dark.

Both camera-based motion detection and PIR sensors are effective in detecting motion. At night, due to its infrared heat sensing technology, the PIR model is a little more effective. However, camera motion detection can be a little more accurate as it isn’t triggered by irrelevant sources of heat.

Factors affecting motion detection

We’ve already discussed how the effectiveness of the heat sensor is affected by its positioning. Well, the same applies to motion detector technology. Therefore, it’s imperative that your video doorbell, equipped with motion detection, is installed at the right height and angle.

The video camera needs to be able to cover the entire front of your property, so choose one with a field of vision of 120 degrees or more. You’ll also benefit from one with a zoom function. Don’t set the doorbell too high up on the door, or the motion sensor will be triggered by all manner of things in the street beyond.

Some examples of issues created by incorrectly positioned video doorbells are false alerts from passing cars, as well as people and animals who are simply roaming the street and not coming anywhere near your home.

Most video doorbells that rely on cameras to detect motion will have adjustable motion zones. What this means is that you can configure the motion zone to encompass either a broader or smaller zone. If you find the camera is being triggered erroneously, try narrowing the field of vision. However, don’t make the detection zone so small that it becomes ineffective in alerting you to potential danger or theft. This applies to both camera-activated motion detection and PIR motion detection technologies.

Additional features enhancing motion detection

Another handy feature found in video doorbells is two-way audio. What this means is that the doorbell camera has an in-built speaker. Whoever is at the door can announce themselves, and you can also reply from inside your home or even via your smartphone if you are out. This is made possible via an app with two-way talk.

One advantage of two-way audio is if a stranger is at your door, you can interrogate them first before risking opening the door to them. You can even use the audio to call the kids inside.

Push notifications will alert you when the camera has been triggered and starts recording, whether it’s somebody visiting your home or a delivery driver who has just dropped off a package at your front door.

You want surveillance of your home to be covered 24/7, and that’s why a camera equipped with night vision is essential. This feature enhances the camera’s ability to detect motion and clearly record footage all through the night for added protection.

Best practices for optimising motion detection

As previously mentioned, you don’t want to mount your video doorbell too high, or it will detect unrelated motion and keep triggering the camera and sending alerts. The reason people do this is they believe it needs to be mounted high up on the door to capture people’s faces. The fact is, it doesn’t (and shouldn’t) be installed at such a height. Ideally, position the camera about 122cm (or 48in) above the ground for optimum results. You’ll still be able to see who’s at the door due to the field of vision of the camera.

If your doorbell is battery-powered, always make sure to replace or recharge the batteries when you receive a notification that power is almost depleted. As most video doorbells connect to the internet and smart home devices, they come with software that periodically needs to be updated with the latest patches.

Talk to us about video doorbells

At Smart Security, we can advise you on the best model of video doorbell for your needs, as well as perform professional installation services. So, contact us today for further information or to arrange an appointment.