A 4k security camera is the new best tech to monitor your property in rich clarity and detail. But is the resolution clear enough to capture license plates? If yes, how far away can a security camera read a license plate of a moving vehicle?
Well, 1080p is the standard CCTV resolution. And as we’ve mentioned in several of our past posts, the picture quality is ideal for general-purpose monitoring. You could identify the face of a person you know up to 20 feet away and 8-13 feet from a stranger.
Now, the way a security camera tries to identify a person is more or less the same used to read a license plate. But when dealing with a moving vehicle, you’ll be surprised to find even a 4K system inadequate for the task.
What Makes a Security Camera Good to Read a License Plate?
In this article, we’ve put together some crucial information you should know on how far away a security camera can read a license plate. And the first thing to keep in mind is that the type of system determines it all.
In a regular security camera like Eufy or Arlo, the chances of capturing the license plate will be only on a stationary vehicle. But in a moving vehicle, you’ll get blurry shots as most of these brands don’t exactly have the features for the task.
On the other hand, a dedicated license plate capture camera (or LPC) can efficiently read the license plates of moving vehicles. But a dedicated license plate recognition camera (LPR) is the only type that can be able to read and identify license plates.
If you understand how facial recognition work on security cameras, license plate recognition behaves very much the same. It takes a snapshot and video of the license plates, then converts these pictures into “numerical expressions” for its database.
The “numerical expressions” here can be a list of the vehicles entering and existing on your property. And as with facial recognition, you can not just search through playback history using a specific license plate. It will also be possible to whitelist or blacklist particular vehicles to receive alerts when they enter or leave the camera frame.
Fast forward, the various features that define a good license plate capture/ recognition camera (LPC or LPR) include the type of lens, viewing angle, frame rate, and resolution.
- Type Of Lens:
The type of lens is one of the crucial features determining how far away a security camera can read a license plate.
In license plate capture/ recognition (LPC or LPR) cameras we’ve gone through, they all have a variable focal length. It helps make sure the numbers on the plates are visible even from a car at a distance or moving.
Also, this explains why a PTZ outdoor security camera with optical zoom can read the plates even without built-in license plate recognition.
Another thing, the varifocal lens is one of the easiest ways how to capture license plates at night without extreme blurriness.
- Viewing Angle:
The viewing angle of your camera should be as tight as possible (30 degrees or less) to focus on the plate. An optical zoom lens is often used in dedicated LPC or LPR cameras since you could adjust the viewing angle.
- Video Frame Rate (Fps)
Most of the dedicated license plate capture/ recognition camera usually operates at @60fps. And the reason for this is that the device will capture silky-smooth videos with more details of the object in motion.
A 4K 30fps security camera can also be able to read the license plates of vehicles entering or leaving your property. But it still has a motion blur in a fast-moving vehicle, which makes it less ideal to overlook a busy street.
- Image Sensor:
If using the standard [email protected] camera, the chances to capture the license plate of a moving vehicle are usually very slim. A 1080p camera will be most effective on the task if it has an optical zoom and a high frame rate.
On the other hand, standard [email protected] security cameras can capture license plates of stationary and nearby slow-moving vehicles. But for a fast-moving vehicle, you can only get a smooth video without motion blur if the camera supports a high frame rate of at least 60fps.
How Far Away Can A Security Camera Read A License Plate?
The maximum distance a security camera can read a license plate depends on the features we’ve highlighted above.
In a dedicated license plate capture (LPC) or license plate recognition (LPR) camera, you can read numbers up to 150 feet away. All you have to do is set the camera to zoom in and have the field of view as tight as possible.
We’ve seen some bloggers say the regular home security camera can read a license plate up to 25 feet away. But at the same time, the Arlo community forum has various users complaining that their Ultra camera can’t read license plates 12 feet away.
In the Arlo Pro 4 vs Ultra 2 review, we saw the excess pixelation is because of the field of view. When a simple license place capture camera requires about 30°, Arlo Ultra has an extra-wide viewing angle of 180 degrees.
So, the formula from KINTRONICS to calculate what you can see with your IP camera doesn’t seem to work here. And for this reason, we’re not going to cover it in our guide today.
The only formula we’ve seen effective in determining how far away a security camera read a license plate is for the mounting requirement. And the particular formula requires that you should mount your security camera between 6-18 feet from the ground. Then, the camera, license plate, and ground should maintain a vertical angle between 0°-30°.
If you fancy playing with digits, this angle will vary with the position of the camera from the ground to the license plate area. The further away you want to have your choke point (for reading license plates), the lower the mounting position of your camera.
Regular Camera is for Still License Plates
Technically, the best way to determine how far a security camera can read a license plate is to break down its features. The higher you can zoom in and focus the lens (optical zoom), the farther away it can identify the ID letters of the vehicle.
If the vehicle is still in the parking lot, the regular security camera can read the plates without any issue. Even the 1080p camera should manage to capture all the letters at 10-20 feet away. But when the vehicle is now moving, the camera should be configured to a high frame rate of 60fps to avoid motion blur.
Meanwhile, a regular 4k security camera could read a license plate of a nearby slow-moving vehicle. But you’ll have the best luck with a narrow field of view since the device will be able to focus on the plate instead of everything in the area.