What they don't tell you about "License Plate Cameras"

People generally think "License Plate Camera" means a camera that can look at a license plate and understand what the license plate says.

This isn't what most license plate cameras do.

surveillance industry shortchange

The term "License plate camera" is used more often used on cameras that are good at license plate capture than license plate recognition.

Most license plate cameras focus on technological innovation to improve license plate capture (getting a good enough photo to accurately see a license plate). This is surprisingly difficult, as we talk about below.

License plate capture is not be confused with automatic OCR number-plate recognition which uses computer vision to read and database license plate data. There are good providers of this, for example, Genetec or Luxriot make fantastic products with high accuracy rates, but to be completely clear the camera isn't doing this. The expensive VMS software is doing this with the help of rather intense on-site or cloud-based server(s).

Some companies have started trying to make cameras that can do this internally, but so far those returned poor results: very low accuracy rates. On-camera LPR suffers from collecting and databasing the wrong data (such as "how am I driving?" phone numbers and marketing text on company vehicles), partial data capture (such as only discerning some of the letters/numbers), and missing data issues (inability to recognize plates at all on anything at an angle or vehicles moving faster than 20 MPH.)

Because of this, as a term, "License plate camera" has no consistent definition.

At SCW, we try not to use the misleading term "License Plate Camera." The term just doesn't mean anything in particular. It can refer to several different technical specifications, which may or may be present or even nothing special at all.

The terms you want to use are "License Plate Capture Camera" and "Licence Plate Recognition Camera," depending on what you want, but even these terms are defined differently by each manufacturer.

We carry some cameras that are better than others at license plate capture. We don't carry any cameras that do license plate recognition because the results aren't yet good enough.

So, let's talk about the different specs that can help increase the likelihood that you capture a workable image of a license plate that could be used in a LPR application and then the environmental and lighting considerations you need to take into account when installing a camera to get good quality footage.

I paid extra to get a "special" camera to record license plates, and all I got was this booklet telling me all the ways it won't work.

- everyone who has ordered a 'license plate camera'

What Specs are important to License Plate Capture?

HD resolution

1. Resolution

The quality of the image that you are capturing is, of course, the most important factor in being able to read a license plate. The higher the resolution and the more narrow your field of view, the greater the distance where you can still read the plate.

Every single product that we sell has pictures of a license plates at different distances, so that you can tell which resolution / lens combination fits your needs best.

Headlight Compensation

2. Headlight Compensation

HLC reduces glare and overexposure due to vehicle headlights that directly pointed into the camera. The problem here is that many cheap camera companies say that anything with Headlight Compensation (HLC) is a "License Plate Camera" - including cameras that don't even record in HD. Don't get us wrong: headlight compensation is a necessary spec required to capture front facing license plates, but by itself HLC isn't enough.

Almost all of SCW cameras have headlight compensation (HLC) and it would be pretty silly to call every product a specialty "License Plate Camera."

Wide Dynamic Range

3. Wide Dynamic Range

Instead of using just one set of settings for saturation, brightness, contrast, and sharpness levels, Wide Dynamic Range splits each frame/image into many sections and determines the correct exposure to create a consistent and balanced image. WDR is very useful when recording in situations where different areas of the same scene are going to have varied lighting levels. Most situations where you want to record license plates are going to have these light variations because of headlights and streetlamps.

adjustable shutter speed

4. Adjustable Shutter Speed

Every camera (including security, movie, and regular cameras) operates the same way: a shutter opens which allows light to be absorbed by the image sensor. Then the shutter closes allowing it take the next picture. When recording video, these pictures are taken so quickly that your brain perceives them as fluid, but a movie camera, camcorder, or security camera are all just taking rapid pictures.

The shutter in a camera controls how long the camera takes to take a picture, but faster doesn't mean better. The faster that a camera shutter opens and closes, the more likely that you will get a clear, blur-free image. The longer that the shutter is open, the more light you let in and the better your image will be in low light. Shutters that are open for an extremely long time allow you to take color pictures at night/twilight without having to switch to infrared mode, but will cause motion blur.

There's no one-size fits all approach to this in any situation, but this is especially true when trying to record license plates. Because you have both a fast moving object (the car) and need for detail in low light situations.

All our cameras have adjustable shutter speeds, usually in a range between 1/30s to 1/100,000 of a second.

The Right Specs are Necessary, but...

License plates come in tons of different background and text color combinations, character sizes, and have many variables that change the amount of light that will be reflect off of the plate. At the bare minimum, it is best to have cameras that have WDR, adjustable shutter speed, and headlight compensation.

Getting a quality camera is important, but does not reduce the need to install the camera in an optimal angle of view, facing an area with adequate lighting.

license plates and IR

1. IR Night Vision is a liability with License Plates

Infrared night vision is actually a liability rather than a benefit when trying to record the highly light reflective paint used in license plates.

What you really need is to have a light source which uses full spectrum, natural, ambient light rather than the infrared light used by the camera (IR light is very reflective and combined with the reflective paint used in license plates can reflect too much light and wash out a ). The most effective deployments of license plate capture design their building around their objective, such as guard posts and parking ticket booths. Nothing is going to beat designing your building around capturing plates, but our Knight camera uses an internal PIR sensor to switch from IR to full spectrum, natural white light.

license plates and angle of view

2. Car Bumpers and SUV Contours limit how high you can mount a camera.

To capture license plates reasonably well, the camera must be less than 30 degree angle above the target. If your camera is too high on the wall, the bumper or a SUV's tail end may block your view of the plate on certain car or truck models. Also, as we're about to talk about with horizontal angles, your brain may not be able to read the characters if they are more than a 30 degree angle downward.

Ideally, you want the camera to be slightly lower than the car so that it is exactly flush with the plate.

license plates and angle of view

3. A small change in the angle of a plate can make the text/numbers very hard to read

People have surprisingly limited experience reading text that is not directly facing them and it can very, very hard to read text that is tilted in some way. In this example, the text is only about 15 degrees rotated and it is significantly harder to read the last two characters, despite being the same size and distance.

stop sign

4. Slow down your car so your can slow down your shutter speed.

Ideally you want the vehicle to come to a full and complete stop, or at least slow down to under 5 MPH, within 20 feet of the camera. The slower that the vehicle is moving, the longer your shutter can be open without getting motion blur. This allows you to set the camera to take a better color photo in low light conditions.

Click here for a downloadable PDF of our advice on license plate capture.


  1. The Warrior 2.0 - 26BF2 - 1080P 2MP Fixed Lens Mini Bullet Camera

    In stock.
    Usually ships the same business day if ordered before 2PM EST.

    $150.00


    Resolution

    1080p HD

    1080P @ 30 FPS; 1920 × 1080

    Detect: 100 ft
    Recognize: 50 ft
    Identify: 25 ft


    Processing Power and Compression: Not All 1080P Cameras are Created Equal


    Weather

    weatherproof

    IP67
    Full protection from dust, rain, snow, dew, frost, and sprinklers.

    You can even submerge it for a few minutes.


    Temp

    temperature rating

    Temperature rated from -31°F to 140 °F

    Humidity rated between 10 and 95%.

    Commercial Grade - What are the Differences?


    Lens

    fixed lens

    Fixed: 4mm
    85° of coverage

    Digital Zoom Only

    Learn about the 4 types of Zoom


    Day/Night

    night footage

    Infrared night vision up to 100 FT

    Larger image sensor for low light

    Color video possible until 0.02 lux

    How to get the best footage at night


    Special

    special features

    Digital Wide Dynamic Range

    Seeing in shadows: Understanding WDR



  2. The Viking 4.0 - 26BV4 - 4MP (2x1080P) Multi-Purpose Lens Bullet Camera with Motorized Zoom and Focus

    In stock.
    Usually ships the same business day if ordered before 2PM EST.

    Price: $399.00

    Limited Time DIY Special: $249.00


    Resolution

    4MP UHD Quality

    4MP @ 25 FPS: 2560 x 1440

    Detect: up to 175 ft
    Recognize: up to 125 ft
    Identify: up to 75 ft


    4MP vs 4K


    Weather

    weatherproof

    IP67
    Full protection from dust, rain, snow, dew, frost, and sprinklers.

    You can even submerge it for a few minutes.


    Temp

    temperature rating

    Temperature rated from -31°F to 140 °F

    Humidity rated between 10 and 95%.


    Lens

    varifocal lens

    Motorized Varifocal: 2.8 - 12mm
    91° - 27° of coverage

    Digital Zoom and Optical Zoom

    Learn about the 4 types of Zoom


    Day/Night

    night footage

    Infrared night vision up to 100 FT

    Color video possible until 0.02 lux

    How to get the best footage at night


    Special

    special features

    Alarm Input and Output

    Audio Input and Output
    Audio Input/Output FAQ

    Micro-SD Card Slot

    True WDR (up to 120 dB)

    Seeing in shadows: Understanding WDR



  3. The Knight 2.0 - 26BV2-W - 2MP Camera with Security Light. Designed for Restricted Access Areas

    In stock.
    Usually ships the same business day if ordered before 2PM EST.

    $549.00


    Resolution

    1080p HD

    1080P @ 30 FPS; 1920 × 1080

    Detect: up to 125 ft
    Recognize: up to 75 ft
    Identify: up to 50 ft


    Processing Power and Compression: Not All 1080P Cameras are Created Equal


    Weather

    weatherproof

    IP67
    Full protection from dust, rain, snow, dew, frost, and sprinklers.

    You can even submerge it for a few minutes.


    Temp

    temperature rating

    Extreme Cold Temperature rated from -40°F to 140 °F

    Humidity rated between 10 and 95%.


    Lens

    varifocal lens

    Motorized Varifocal: 2.8 - 12mm
    91° - 27° of coverage

    Digital Zoom and Optical Zoom

    Learn about the 4 types of Zoom


    Day/Night

    night footage

    Infrared night vision up to 165 FT

    Integrated Full Spectrum Motion Light

    Larger image sensor for low light

    Color video possible until 0.001 lux

    How to get the best footage at night


    Special

    special features

    DC-Iris

    Alarm Input and Output

    Audio Input and Output
    Audio Input/Output FAQ

    Micro-SD Card Slot

    True WDR (up to 120 dB)

    Seeing in shadows: Understanding WDR



  4. The Archer 2.0 - 26BV2-L - 2MP Long Range, Low Light Bullet Camera with Motorized Zoom and Focus

    In stock.
    Usually ships the same business day if ordered before 2PM EST.

    $799.00


    Resolution

    1080p HD

    1080P @ 30 FPS; 1920 × 1080

    Detect: up to 450 ft
    Recognize: up to 350 ft
    Identify: up to 300 ft


    Processing Power and Compression: Not All 1080P Cameras are Created Equal


    Weather

    weatherproof

    IP67
    Full protection from dust, rain, snow, dew, frost, and sprinklers.

    You can even submerge it for a few minutes.


    Temp

    temperature rating

    Extreme Cold Temperature rated from -40°F to 140 °F

    Humidity rated between 10 and 95%.


    Lens

    varifocal lens

    Long Range Motorized Varifocal: 4.7 - 47mm
    65° - 9° of coverage

    Digital Zoom and Optical Zoom

    Learn about the 4 types of Zoom


    Day/Night

    night footage

    Infrared night vision up to 300 FT

    Larger image sensor for low light

    Color video possible until 0.001 lux

    How to get the best footage at night


    Special

    special features

    P-Iris

    Alarm Input and Output

    Audio Input and Output
    Audio Input/Output FAQ

    Micro-SD Card Slot

    True WDR (up to 120 dB)

    Seeing in shadows: Understanding WDR



  5. The Sharpshooter 2.0 - 26BV2-XL - 2MP Super Long Range, Low Light Bullet Camera with Motorized Zoom and Focus

    In stock.
    Usually ships the same business day if ordered before 2PM EST.

    $999.00


    Resolution

    1080p HD

    1080P @ 30 FPS; 1920 × 1080

    Detect: 950 ft
    Recognize: 850 ft
    Identify: 800 ft


    Processing Power and Compression: Not All 1080P Cameras are Created Equal


    Weather

    weatherproof

    IP67
    Full protection from dust, rain, snow, dew, frost, and sprinklers.

    You can even submerge it for a few minutes.


    Temp

    temperature rating

    Extreme Cold Temperature rated from -40°F to 140 °F

    Humidity rated between 10 and 95%.


    Lens

    varifocal lens

    Super Long Range Motorized Varifocal: 6.5 - 143mm
    59° - 3° of coverage

    Digital Zoom and Optical Zoom

    Learn about the 4 types of Zoom


    Day/Night

    night footage

    Infrared night vision up to 650 FT

    Extremely Large image sensor for low light

    Color video possible until 0.002 lux

    How to get the best footage at night


    Special

    special features

    DC-Iris

    Alarm Input and Output

    Audio Input and Output
    Audio Input/Output FAQ

    NOT POE

    Micro-SD Card Slot

    True WDR (up to 120 dB)

    Seeing in shadows: Understanding WDR