45-219 12.5 mm Dia. N-BAF10/N-SF10 Negative Achromatic Doublet; EFL=-25mm MgF2 400-700nm

The 45-219 is a high-quality negative achromatic doublet lens, sourced from the renowned optical vendor, Edmund Optics. This lens, with a diameter of 12.5 mm, is designed for use in the visible spectrum, specifically between 400-700nm.

The lens features a unique geometry, with an effective focal length (EFL) of -25mm, making it suitable for a wide range of optical applications. The inner radius of the lens is 0, while the outer radius is also 0, indicating a symmetrical design. The first radius of curvature (r1) is -17.75, and the second radius (r2) is 12.17, while the third radius (r3) is 109.75.

The lens is constructed from two types of high-quality glass, N-BAF10 and N-SF10, both from Schott. These materials are known for their excellent optical properties, making them ideal for use in precision optical systems. The lens also features a center thickness of 2mm, with a slightly increased thickness at the edge (5.74mm) to ensure structural integrity.

The lens is coated with Edmund Optics' standard MgF2 coating on both the front and back surfaces, providing improved transmission in the visible spectrum. This coating is part of the standard curve offered by Edmund Optics, ensuring consistent performance across different lenses.