The 89-177 is a high-quality double-convex lens, sourced from the renowned optical vendor, Edmund Optics. This lens, with a base shape of a circle, has a diameter of 25mm and a focal length of 35mm, making it suitable for a wide range of optical applications.
The lens is made from n-BK7 Schott, a popular optical glass known for its excellent transparency and low auto-fluorescence. The geometry of the lens includes an edge thickness of 2mm and a center thickness of 6.6mm, contributing to its robust construction. The effective focal length (EFL) is 35mm, and the radii of curvature are 35.09mm for the first surface and -35.09mm for the second surface. The back focal length (BFL) is 32.81mm.
The lens features a VIS-EXT coating on both the front and back surfaces, designed to enhance its performance in the visible spectrum, specifically between 350-700nm. This coating reduces surface reflections, improving transmission and overall image quality.