License plate recognition (LPR), or capture, is a key component of most security camera systems. But there is more to license plate capture than installing a regular security camera. The security camera needs to be placed in the right location, at the right height, and have the proper lens. The area also needs the proper lighting to capture a license (LP) plate. These are keys to getting the best results.
Capturing license plates on a highway differs from what businesses and construction sites need. Highways use costly high-speed license plate recognition cameras that are designed to collect high-quality images. For many applications, a good quality camera with the right lens and proper settings in the video management software is ideal. Business and construction sites don’t require an investment into such an expensive license plate recognition camera.
Megapixel, Lenses and Camera Placement
Higher megapixels help capture more details, but it does not mean that you need to break the bank. A camera with 3MP to 5MP will work well to capture licenses plates, as long as they are correctly placed and have the right lens. Cameras cannot be mounted too high, or else the angle of the view will be too steep. Aim to maintain around 30-degrees, or you will capture the tops of vehicles rather than the license plates. The wrong angle will also result in blinding the camera from light bouncing off the vehicles (or the vehicles lights).
What is the right height?
The ideal mounting height for most security cameras designed for license plate (a license plate recognition camera) is 12-15ft. The further away the camera is to the LP, the higher the camera can be mounted (because your angle of view is lower when looking further away). But as you try to capture further away from the camera, you will need to increase the size of the lens.
What is the right lens?
The lens makes the difference when capturing licenses plates. You cannot have a wide-angle lens meant for general surveillance and still capture license plates. Many customers make this mistake when choosing security cameras because they want to cover as much area as possible with a single camera. The issue is that the wider the view, the lower your ability to zoom into smaller items. Most security cameras, for general surveillance, have a 3-8mm lens. The lower the number, the wider the view. The higher the number, the narrower the view (lens sizes are measured in millimetres).
For most construction sites, commercial plazas, and buildings with smaller parking lots, a 3-5Mp security camera with a 9-22mm lens is perfect. A higher megapixel camera with a 30-80mm lens is best for larger manufacturing and logistics businesses because these businesses typically have larger parking lots with entrances that are usually further away from the building. In these scenarios, the license plate recognition camera can be mounted higher because the angle from the building to the parking lot entrance is lower and farther away.
License Plates & General Surveillance: One Camera Can’t Do Both
Two cameras are best to capture license plates and general surveillance, with one security camera dedicated to license plate capture (a license plate recognition camera) and the other for general surveillance. Using one camera for both will result in blurry images and not capturing plates.
Low Light Makes Things Worse
Lower light causes further blurriness in fast-moving images, especially at night. For example, if the vehicle happens to stop in front of your wide-angle camera (day or night), the chances of getting an LP are higher. However, someone will rarely stop right at the perfect spot.
Why does the view of your License Plate Security Camera look bad?
The view will be ineffective for anything other than license plate capture with a dedicated LPR security camera because the lens is almost fully zoomed in. During the day, objects in view will appear very large, but the outcome will be excellent license plate details.
LPR Cameras Still Work at Night
At night, the picture will look worse because the lack of light makes the camera seem like it is not working at all. However, when a vehicle drives by, the light will reflect off the license plate to allow for capture. A good balance of the camera settings will help control how much light gets in during the day (washing out the image). If not enough light gets in at night, the image will be too black.
Capturing license plates with your security cameras can be a challenge. When looking at cameras, consider the megapixels, lens and placement. The key to getting the best results is in the planning.
Who We Are
Spotter Security is a Canadian security solutions company based in Markham, Ontario. We have been in the physical security industry for more than 17 years. Our clients include many construction companies, manufacturing plants, commercial plazas, logistics companies, warehouses, data centers, education institutes and other commercial properties. The main services we provide include video surveillance systems, security cameras, live video monitoring for construction sites, and access control systems.
Get in Touch
We will install a customized security system integrated with LPR cameras tailored to work with your current system. Contact us to learn more about the benefits of LPR cameras and how Spotter Security can help. Call us now at 1(877) 557-3175, or fill in our form to get in touch with us. Spotter Security will help you gain control over your business security.
Written by : Carlo Di Leo
At the age of 24, with no experience in the security industry or any money in the bank, Carlo quit his job and started Spotter Security from his parent's basement. Founded in 2004, Spotter grew from a single man operation into a multi-million dollar security system integrator that caters to businessess and construction sites across Canada.
