Neutral Density Filter

https://www.atoptik.com/products/neutral-density-filter.html Neutral density glass filter use the absorption or reflection properties of substances to light to attenuate light intensity. After the light from the visible light region to the near-infrared light region passes through the neutral density filter, different wavelengths are attenuated in the same proportion. The optical element maintains approximately the same transmittance of light energy in a wide band. Also known as optical neutral density filter, neutral filter, ND filter, attenuation filter, fixed density filter, etc. Neutral Density (ND) filters can attenuate the light intensity. After the light from the visible light region to the near-infrared light region passes through the neutral density filter, different wavelengths are attenuated in the same proportion, so that the optical element maintains approximately equal light energy transmission in a wide band. over rate. Also known as neutral density filter, neutral filter, ND neutral density filter, attenuation filter, fixed density filter, etc. Neutral Density (ND) filters are designed to uniformly reduce transmission over a specific part of the spectrum. ND filters are generally defined by their optical density (OD), which describes the amount of energy blocked by the filter. High optical density values indicate very low transmission, and low optical density indicates high transmission (Equation 1-2). ND filters can be stacked to achieve customized optical densities. To calculate the final system OD, simply add the OD of each filter.