The ADL MZ40X2751DPFIR-T 2/3″ 27 – 1070mm motorised 40X long-range zoom lens has a 3MP resolution making it suitable for long-distance surveillance applications. It is designed for camera sensors up to 2/3″ and has a DC auto iris, and motorised zoom and focus with presets as well as a F5.1 maximum aperture. In addition the lens is IR Corrected (ED aspherical glass) for Day/Night cameras, temperature focussing correction, as well as back focus and boresight adjustment.
The MZ40X2751DPFIR-T also has a “fog free” feature where a visible light filter can be switched in to the lens. This cuts Visible light (400nm~700nm) and transmit light around 850nm to enhance visibility especially when there is mist or thick fog.
This lens is a perfect lens companion for a wide range of High Definition IP and other security cameras and is the perfect tool for long distance / covert surveillance. Typical applications could include border security, airports, and harbours.
The “fog free” function on this lens is designed to improve image quality in obscured weather conditions (fog, mist, dust, smoke, etc). This lens uses a special filter to remove all light wavelengths below 800nm (mainly visible light) from the image and transmit light greater than 800nm into the near infra-red light spectrum. The science behind this feature is that different wavelengths of light can penetrate through air-borne water droplets and particulates (fog, mist, dust, smoke, etc) to varying degrees. When light encounters water droplets or dust particles it is deflected from the direct path making the image increasingly hazy. Infra red light has a longer wavelength than visible light so has a much better chance of “going around” the particles and reach the camera sensor! The filter is deployed because visible light and infra red light focus at a slightly different distance meaning that if the lens is focussed at a point in the infra red spectrum the visible light will blur. When you remove the visible light the image will appear sharper despite the amount of light reaching the sensor has decreased.