47-639-INK 25 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=75mm VIS 0° 425-675nm

The 47-639-INK is a high-quality achromatic doublet lens, sourced from the renowned optical components manufacturer, Edmund Optics. This lens boasts a 25 mm diameter and an effective focal length (EFL) of 75 mm, specifically designed for the visible light spectrum ranging from 425 to 675 nm.

The lens is meticulously crafted from two types of Schott glass: N-BK7 and N-SF5. These materials are chosen for their excellent optical properties, contributing to the lens's high performance. The lens features a standard curve coating on both the front and back surfaces, identified as 'edm vis-0 std curve'. This coating enhances the lens's durability and overall light transmission, making it suitable for a wide range of applications.

The lens geometry is intricately designed, with a center thickness of 7 mm and an edge thickness of 6.97 mm. The lens's inner and outer radii are 0, and it has a concave-convex-concave shape, denoted by the radii values of r1=-46.44 mm, r2=33.77 mm, and r3=-95.94 mm. The lens also features a central thickness 'a' of 2.5 mm.

This lens is a multiplet, meaning it is composed of multiple elements. Multiplets are often used in optical systems to correct chromatic aberrations and improve image quality. The 47-639-INK is no exception, offering superior image quality and minimal chromatic aberration.