There are two types of neutral density filters: reflective and absorbent. Reflective neutral density filters consist of a metal coating on a glass substrate, which primarily reflects light back to the source. Absorptive neutral density filters use a glass substrate to absorb a certain percentage of light.Reflective filters use the principle of thin-film interference to transmit part of the light while reflecting the rest, which can easily cause stray light and reduce experimental accuracy. Absorptive filters, on the other hand, involve the material itself or the material doped with certain elements absorbing specific wavelengths of light, while having little to no effect on other wavelengths.Neutral density filters are widely used in applications where light control is necessary, such as photography, laser equipment, optical instruments, and more. They help users better control exposure times, aperture sizes, and achieve certain special effects without overexposure due to excessive light
Material | optical glass |
Shape | Round,Square or Special shape |
Diameter&Tolerance | 1-400±0.1mm |
Thickness&Tolerance | 0.1-3±0.05mm |
Transmission | As per your need |
Flatness | 1λ or better |
Surface quality | 60/40 or better |
Can be customized according to your requirements