47-637 25 mm Dia. N-BAF10/N-SF10 Achromatic Doublet; EFL=50mm VIS 0° 425-675nm

The 47-637 is a high-quality achromatic doublet lens, boasting a 25 mm diameter and an effective focal length (EFL) of 50mm, specifically designed for the visible spectrum ranging from 425 to 675nm. This lens is sourced from the renowned optical vendor, Edmund Optics, and is available for purchase through their official website.

The lens is constructed from two types of Schott glass, N-BAF10 and N-SF10, which are renowned for their excellent optical properties. The front and back surfaces of the lens are coated with the EDM VIS-0 standard curve coating, providing improved light transmission and reduced surface reflections.

The lens geometry is meticulously designed, with a thickness of 8.79mm at the edge, a center thickness of 9mm, and a central thickness 'a' of 2.5mm. The lens features three radii of curvature: r1 at 34.53mm, r2 at -21.98mm, and r3 at -214.63mm. The inner and outer radii are both zero, indicating a circular shape.

This lens is classified as a multiplet, a type of lens composed of multiple elements. Multiplets are often used in optical systems to correct chromatic aberrations and improve image quality. The 47-637 is a doublet, meaning it is composed of two elements, which provides a good balance between complexity and performance.