47-719 30 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=200mm VIS 0° 425-675nm

The 47-719 is a high-quality achromatic doublet lens, boasting a 30 mm diameter and an effective focal length (EFL) of 200mm, specifically designed for the visible light spectrum ranging from 425 to 675nm. This lens is sourced from the reputable optical vendor, Edmund Optics, and is available for purchase through their website.

The lens is constructed from two types of glass: N-BK7 and N-SF5, both from Schott. The N-BK7, a borosilicate crown glass, is known for its excellent optical transmission and low dispersion, making it a popular choice for many optical applications. The N-SF5, a dense flint glass, further reduces dispersion and contributes to the lens's achromatic properties.

The lens features a sophisticated geometry, with a thickness of 6.15mm at the edge, a central thickness of 5mm, and a central thickness of 2.5mm on the 'a' side. The lens's first radius of curvature (r1) is 123.77mm, the second radius (r2) is -89.22mm, and the third radius (r3) is -259.43mm. The lens's inner and outer radii are both zero, indicating a circular shape.

The lens is coated with Edmund Optics' standard Vis-0 coating on both the front and back surfaces, which are designed to optimize transmission within the specified visible light spectrum. This coating helps to minimize reflection and increase the lens's overall efficiency.