ND05B Dia. 25 mm Unmounted Reflective ND Filter; Optical Density 0.5

The ND05B is a circular Neutral Density Filter with a diameter of 25 mm and a thickness of 1 mm, sourced from the renowned optical component vendor, Thorlabs. This filter is designed to reduce the intensity of incident light without altering its color composition, making it an essential tool for various optical applications.

The filter's Neutral Density (ND) coating, denoted as 'tho nd05' on both the front and back surfaces, boasts an Optical Density (OD) of 0.5. This specific OD value signifies that the filter reduces the light intensity by a factor of 1.41, offering a subtle yet effective light reduction capability.

The ND05B filter is crafted from N-BK7 Schott, a high-quality borosilicate glass known for its excellent optical properties, including low auto-fluorescence, high homogeneity, and superior transmission in the visible spectrum. This material choice ensures the filter's performance and durability, making it suitable for rigorous optical settings.

The filter's 'Thin Lens' shape further enhances its usability, as it minimizes the risk of vignetting and ensures seamless integration with various optical systems. The 'Unmounted' characteristic implies that the filter does not come with a mount, providing users the flexibility to pair it with their preferred mounting solution.

For those interested in learning more or purchasing this item, Thorlabs' official website (https://www.thorlabs.com/thorproduct.cfm?partnumber=ND05B) offers additional information and confirms its availability.