The 89-127 is a double-convex lens, characterized by its circular base shape and spherical geometry. The lens has a diameter of 5mm and a focal length of 20mm, making it a compact yet powerful optical component. The edge thickness measures 1.19mm, while the center thickness is slightly greater at 1.5mm, providing a balanced optical path.
This lens is made from n-BK7 Schott, a high-quality optical glass known for its excellent transparency and low dispersion. The lens is coated with EDM VIS-EXT on both the front and back surfaces, enhancing its transmission capabilities within the visible spectrum (350-700nm). This coating ensures high-quality image reproduction by reducing surface reflections and improving light transmission.
The lens's inner and outer radii are 0mm, indicating a symmetrical design that minimizes optical aberrations. The effective focal length (EFL) is 20mm, and the back focal length (BFL) is 19.5mm, providing a clear and focused image.