The Tiffen 49mm apeX Hot Mirror IRND 3.0 Filter is a combination of both a hot mirror infrared control filter and a 3.0 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.This filter is constructed using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding flat to a tolerance of 1/10,000th of an inch.Infrared control filter helps to block infrared pollution from affecting the color fidelity of imagery; this enables a wider color gamut and truer colors, especially noticeable in the darker regions of the image.3.0 neutral density filter provides a 10 stop exposure reduction.Ideal for use with HD cameras without an integrated infrared-blocking filter.Hot mirror filter blocks infrared pollution from both near and far regions of the spectrum while allowing all visible light to pass.