The 89-169 is a double-convex lens, characterized by its circular base shape and spherical geometry. The lens, sourced from Edmund Optics, boasts a diameter of 20mm and a focal length of 25mm, making it a versatile choice for various optical applications. The lens's edge thickness is 1.35mm, while its center thickness is 4mm, providing a solid and robust structure.
The lens's effective focal length (EFL) is 25mm, and its first and second radii (R1 and R2) are 38.34mm and -38.34mm respectively, contributing to its double-convex design. The back focal length (BFL) is 23.86mm, and both the inner and outer radii are 0mm, indicating a uniform curvature throughout the lens.
The lens is made from n-SF11 Schott, a high-index glass with excellent optical properties. It is coated with EDM VIS EXT on both the front and back, a coating designed for visible light wavelengths ranging from 350 to 700nm. This coating enhances the lens's performance by reducing surface reflections and increasing transmission, making it an ideal choice for applications that require high light transmission and clarity.