The SL183A lens provides an ultra-wide field of view without distortion. The lens incorporates patented Linear Optical Technology® which allows an ultra-wide field of view without barrel distortion found in other wide angle lenses. This design allows increased resolution at the edges of the image thus increasing the probability of detection in security systems.

The SL183A is a high-quality lens designed to allow the installer to take full advantage of the high resolution of HD and multi megapixel cameras. The lens can be used on cameras up to five megapixel resolution giving a crisp image from edge to edge.

This varifocal lens also includes an easy zoom feature which allows the installer to focus the lens once and then adjust zoom or magnification to give the best field of view. Only minor focus optimization is required after zooming, meaning that there is no need for the iterative focus-zoom-focus method of setup required for other varifocal lenses.

The lens is IR corrected for use with true day/night cameras. This IR correction focuses IR light from artificial illumination at the same plane as the visible light allowing the image to remain in focus when the day/night camera switches to night mode. Unlike lenses without IR correction, the night image will not be out of focus when using IR illumination.