This lens provides an ultra wide field of view without distortion. It is a varifocal lens allowing the user to optimize the field of view from wide angle to ultra wide. It is a high quality lens designed to allow the installer to take full advantage of the high resolution of HDTV and multi megapixel cameras. The lens incorporates patented Linear Optical Technology which allows an ultra wide field of view without barrel distortion. The rectilinear design allows increased resolution at the edges of the image thus increasing the probability of detection. The focal length is 1.8 - 3.0 mm and the lens fast aperture (F-number) is 1.8. The Theia Varifocal Ultra Wide Lens 1.8 - 3.0 mm with DC-iris is recommended for use with the AXIS P13 Series and AXIS Q16 Series. The lens is day/night corrected and therefore no adjustments will be needed when the IR-cut filter of the day/night camera disengages.