Reflective Neutral Density (ND) Filters

Reflective Neutral Density (ND) Filters have constant density values across the surface. The transmission-to-reflection ratio varies with density selection, whose relationship can be explained by the equation: T(Percent Transmission) = 10^-OD x 100%. 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. In stacks, the total density is the sum of each filter's density. Reflective Neutral Density (ND) Filters are used primarily for attenuating light over a wide spectral range. They are often used in laser and photometer applications, where excessive power can cause damage or inaccurate results. For best results, orient the mirrored side toward the source at a 0° angle of incidence. 

Note: Low optical density filters (0.1, 0.15, and 0.2 OD) are coated with thin layers of Inconel and their performance may shift overtime. To prolong the lifetime of these filters, we recommend using non-contact cleaning methods (such as compressed air) and avoiding the use of these filters in humid environments to prevent oxidation. Using contact cleaning methods such as solvents will damage the coating and the product will no longer meet the advertised specifications. 

Note: Due to supply chain issues, our kits may be delivered with an alternative packaging solution in place of a wooden box. For any questions, please contact kits@edmundoptics.com.