Mobotix M12D-Sec-N135 LPF Information:
Mobotix M12 Dual lens camera with 1x43mm Wide angle lens and 1x135mm Telephoto lens with special Long Pass Filter which eliminates the light below 680nm. This megapixel surveillance camera is specifically designed for accurate visual verification of license plates at night.
Long pass filters (LPF) are useful for isolating specific regions of the spectrum above a specified value, to transmit a specific range of wavelengths, and block wavelengths below this value. The cut-on wavelength is where the long pass filter stops reflecting (blocking) and starts transmitting. LPF is often used in a range of applications such as heat detection, astronomy, IR research and long range night surveillance.