47-642 25 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=125mm VIS 0° 425-675nm

The 47-642 is a high-quality achromatic doublet lens, boasting a 25 mm diameter and an effective focal length (EFL) of 125mm, specifically designed for the visible light 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 glass, N-BK7 and N-SF5, both from Schott, ensuring superior optical performance. The N-BK7, a borosilicate crown glass, is known for its excellent transmission properties and low dispersion, making it ideal for use in achromatic doublets. The N-SF5, a dense flint glass, further reduces chromatic aberration, contributing to the lens's high-resolution image quality.

The 47-642 features a complex geometry, with a central thickness of 6mm, edge thickness of 6.89mm, and radii of curvature of 76.28mm, -54.55mm, and -162.43mm for the first, second, and third surfaces, respectively. This design allows for precise control of optical aberrations, resulting in a lens with high image quality and low distortion.

The lens is coated with Edmund Optics' standard Vis-0 coating on both the front and back surfaces, providing excellent anti-reflection properties within the specified visible light spectrum. This coating enhances the lens's transmission capabilities, reducing unwanted reflections and improving overall image contrast.