NiSi will soon be offering full spectrum gray filters for cinema setups, i.e. for use in matte boxes. They are available in 4x5.65" and 6.6x6.6" sizes and are designed to provide completely neutral, consistent color reproduction over a density range of 0.3 to 2.4 - the light is transmitted evenly through the spectrum of ultraviolet, visible and near-infrared wavelengths.
NiSi FSND filters
The FSND filters (FS as in Full Spectrum) in the thicknesses 0.3, 0.6, 0.9, 1.2, 1.5, 1.8, 2.1, 2.4 are made of optical crown glass (H-K9L) with precise flat and parallel surfaces. A newly developed double-sided nano "Ti" (titanium) coating is designed to minimize stray light and reflections and maintain overall contrast. A hydrophobic and oleophobic coating ensures quick and easy cleaning.
NiSi has not yet revealed exactly when the full-spectrum gray filters will be available or how much they will cost.
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