Optolong UV/IR Cut 1.25" FIlterOptolong UV IR Cut filter is designed for ultraviolet and infrared wavelength blocking to improve sharpness of the image as most of the optics are designed for the visible spectrum, because its very difficult to create a lens with the same focal point for the visible and IR spectrum. It is used on a digital camera and the video, which do not have an IR protection filter toward an image sensor or were remodeled. This is important because unfiltered CCD