The Tiffen 6.6 x 6.6" Full Spectrum IRND 0.9 filter is a combination of an infrared control filter and a 0.9 neutral density filter. An IRND is ideal for HD cameras, which have greater low-light sensitivity and, consequently, increased susceptibility to IR contamination. When using a standard neutral density filter to counter the increased light sensitivity offered 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 overflow of infrared light reaching the sensor whilst maintaining the additional exposure benefits of a neutral density filter. This filter is constructed from Water White glass and is manufactured using ColorCore technology, a process that involves laminating the filter substrate between 2 pieces of optical glass and grinding it flat to a tolerance of 1/10,000th of an inch. This filter measures 6.6 x 6.6" / 167.6 x 167.6 mm. - The infrared control filter helps block infrared pollution that affects the colour fidelity of images; this allows a wider colour gamut and truer colours, particularly visible in the darker regions of the image. - The 0.9 neutral density filter provides a 3-stop exposure reduction. - Water White optical glass for excellent clarity. Specifications