Our TECHSPEC® Absorptive Neutral Density Filters and TECHSPEC® NIR Non-Reflective Neutral Density Filters are now available in M25.5 and M30.5 mounts for imaging lenses. Neutral Density (ND) filters are useful for limiting the amount of light that reaches the sensor of a camera. Using ND filters rather than the iris of your lens allows the imaging system to limit the depth of field of the image, eliminating parallax errors and other image artifacts that may limit the usefulness of your machine vision software.
We have specially designed our mounts to hold filters up to 6.5mm in thickness, allowing the user to stack multiple ND filters together to create custom transmission filters. Optical Densities are additive, meaning a filter stack of a 0.4 OD filter and a 1.3 OD filter will produce a 1.7 Optical Density.