ND40A Dia. 25 mm ND Reflective Filter; SM1-Threaded Mount; Optical Density 4.0

The ND40A is a Neutral Density Filter with a diameter of 25 mm, designed for use with optical systems requiring significant light reduction. Manufactured by Thorlabs, a leading vendor in the field of optical components, this filter boasts an impressive Optical Density (OD) of 4.0, ensuring a substantial reduction in light intensity while maintaining color neutrality.

The filter is constructed from N-BK7 Schott, a high-quality borosilicate glass known for its excellent optical properties. It features a Thin Lens shape, which minimizes thickness and potential aberrations, contributing to superior image quality. The front and back surfaces of the filter are coated with THo ND40, a specialized coating that enhances the filter's performance and durability.

The ND40A is equipped with an SM1-threaded mount, enabling seamless integration with various optical systems. This mount is compatible with a wide range of components, providing users with the flexibility to build and customize their optical setups according to their specific needs.

For those seeking a reliable, high-performance Neutral Density Filter, the ND40A is an excellent choice. With its robust construction, advanced coating, and versatile mount, it promises to deliver consistent, high-quality results in a variety of applications.