The 89-123 is a double-convex lens with a diameter of 4.5mm and a focal length of 9mm, making it a compact and powerful optical component. This lens is sourced from Edmund Optics, a reputable vendor known for their high-quality optical elements.
The lens is made from n-BK7 Schott, a popular optical glass due to its excellent optical properties and chemical durability. The base shape of the lens is circular, ensuring a wide field of view and minimal distortion.
The geometry of the lens is meticulously designed, with a thickness of 1.8mm at the edge and 2.38mm at the center. The effective focal length (EFL) is 9mm, and the radii of curvature are 8.88mm for both the first and second surfaces. The back focal length (BFL) is 8.16mm, which is crucial for determining the position of the lens in an optical system.
The lens features VIS-EXT coatings on both the front and back surfaces, specifically designed for the visible spectrum (350-700nm). These coatings enhance the lens's performance by reducing surface reflections and increasing transmission, resulting in improved image quality and contrast.