47-669 12.5 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=75mm VIS 0° 425-675nm

The 47-669 is a high-quality achromatic doublet lens, boasting a 12.5 mm diameter and an effective focal length (EFL) of 75mm, 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 website.

The lens is constructed from two types of Schott glass: N-BK7 and N-SF5. The N-BK7, a borosilicate crown glass, is known for its excellent optical transmission and low dispersion, making it ideal for use in achromatic doublets. The N-SF5, a dense flint glass, further reduces dispersion, ensuring the lens delivers sharp, clear images with minimal chromatic aberration.

The lens geometry is meticulously designed, with an inner radius of 0mm, an outer radius of 0mm, and a center thickness of 3mm. The edge thickness is 3.97mm, while the front and back radii are 46.44mm and -33.77mm respectively. The lens also features a -95.94mm radius on the third surface, contributing to its superior optical performance.

The 47-669 lens is coated with Edmund Optics' standard Vis-0 coating on both the front and back surfaces. This anti-reflection coating is specifically designed for the visible light spectrum, further enhancing the lens's optical performance by reducing surface reflections and increasing transmission.