Edmund Optics Inc. Reflective ND Filter 0.4 Optical Density 50mm Square NT64-140

Spectrally Flat Maximum Accuracy and Neutrality at Moderate Price Use Stacks to Create Intermediate Density Values These filters have constant density values across the surface. The transmission to reflection ratio varies with density selection. In stacks, the total density is the sum of each filters density. ND filters are used primarily for the attenuation of light over a wide spectral range. They are often used in laser and photometer applications, where excessive power can cause damage or inaccurate results. Orient mirrored side toward source at 0® angle of incidence.Optical Density exhibits an additive relationship; for example, stacking filters with OD values of 0.6 and 0.9 yields a resultant density of 1.5. The optical density is related to the transmission by the following equation: T = 10-OD x 100 = Percent Transmission. Reflective Neutral Density Filter Kits Reflective Neutral Density Filter Kits are available with either 8 or 14 optical densities. The kits with 8 filters include our most popular filters, with densities of 0.3, 0.5, 1.0, 1.3, 1.5, 2.0, 2.5, and 3.0. The kits with 14 filters include all available densities, except for 3.0. Kits are ideal for determining precise system optical density requirements. Custom densities are available for OEM applications.