13-118 50 mm Dia. Hoya ND-25 Absorptive Neutral Density Filter; OD 0.6 425-675nm

This is the 13-118 Hoya Neutral Density Filter, a high-quality optical component designed for a wide range of applications. Sourced from the reputable vendor Edmund Optics, this filter boasts a 50 mm diameter and a thickness of 2.5 mm, making it a versatile and robust choice for various optical systems.

The filter is of the Neutral Density type, specifically an Absorptive Neutral Density Filter, which reduces the intensity of light entering the optical system without altering its color composition. This is achieved through the use of a special coating, denoted as 'edm 13-101' on both the front and back surfaces, which absorbs a specific portion of the light spectrum.

The wavelength of this filter is 588 nm, indicating its primary effectiveness in the visible light spectrum. The coating is designed to operate within the 425-675nm range, providing a good balance between light absorption and transmission across a broad spectrum.

The filter's geometry is defined by its circular shape and thin lens design, which minimizes optical aberrations and ensures easy integration into various optical setups. The catalog number for this item is 13-118, and it is currently in stock, as indicated by its weblink status.