4 x 5.65" Hot Mirror IRND 1.8 Filter is a combination of both a hot mirror infrared control filter and neutral density filter. A hot mirror IRND is ideal for HD cameras, which have greater low-light sensitivity and, subsequently, an increased susceptibility to IR contamination. When using a standard neutral density filter to counter the increased light sensitivity afforded by the HD sensor, the effects of infrared pollution become more apparent. This filter combines an ND filter with a comparable IR control filter to eliminate the spill of infrared light reaching the sensor while still maintaining the extra exposure benefits of a neutral density filter. The hot mirror filtration incorporates a dielectric mirror in order to combat the effects of both near and far infrared regions of the spectrum.