FNG4025 25 mm Dia. Absorptive Glass Neutral Density Filter 546nm

The FNG4025 is a 25 mm diameter Neutral Density Filter, sourced from the reputable optical components vendor, Knight Optical. This filter is designed with a specific wavelength of 546nm, making it ideal for applications that require precise light absorption at this frequency.

The filter is of the Neutral Density type, which means it reduces the intensity of all wavelengths of light equally, providing a uniform attenuation without altering the color balance. This is particularly useful in various fields such as photography, cinematography, and scientific research where controlling light intensity is crucial.

The filter is made from UVFS MAL-1965 material, a high-quality glass known for its excellent optical properties. It has a base shape of a circle, a standard size in optical applications due to its ease of use and versatility. The filter's thickness is 3.9mm, providing robustness and stability.

The FNG4025 features a special coating on both the front and back surfaces, denoted as 'kni fng40'. This coating enhances the filter's performance and durability, protecting it from environmental factors and ensuring longevity.

The filter's geometry is defined as a 'Thin Lens', indicating a lens with a short focal length compared to its diameter. This feature can be beneficial in applications where space is limited or a wide field of view is required.