1/3" auto iris direct drive day/night lens. The purpose of Pelco’s 13VDIR Series is to compensate for the focus shift that results from the different wavelengths of visible and IR light. IR corrected lenses focus light energy on the same plane. The result is better focus, sharper contrast, and better overall image quality. IR corrected lenses are particularly of benefit to Pelco’s day/night cameras, which see both visible and IR light. IR corrected lenses allow a camera’s imager to take in visible and IR illumination in night conditions (when the IR cut filter is not deployed), while eliminating the problem of IR focus shift.