[License Plate Recognition] Exposure Settings for LPF sensor module (best practice)

In this article, we will explain the recommended exposure settings for the usage of an LPF sensor module for license plate recognition.

The settings are suitable for use both during the day and at night.
We would like to point out that the recommended settings will most likely not fit perfectly for all installations. Therefore, they must always be tested and accepted by the customer.

NOTE: Due to the properties of the Long Pass Filter (LPF), make sure that the camera is equipped with an infrared functional module (optional: external infrared illuminator) and that this is continuously active (no camera automatic).

1) Recommended exposure settings:

Please note the following excerpt from the configuration of a camera for license plate recognition.
Parameters that must be adjusted for the use of an LPF sensor module are:

  • Automatic Contrast: Off
  • Average brightness: 40%
  • Minimum Average Brightness: 20%
  • Night Improvement: Off
  • Sensor Gain Range: High
  • Exposure Time: Max 1/250, Min. 1/16000

2) Expected Result

The following images show the expected results of the exposure setup with LPF sensor module during day and at night.

  • 4K LPF Sensor Module during day:

  • 4K LPF Sensor Module at night: