47-641 25 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=100mm VIS 0° 425-675nm

The 47-641 is a high-quality achromatic doublet lens, boasting a 25 mm diameter and an effective focal length (EFL) of 100mm. This lens is designed for use within the visible light spectrum, specifically catering to wavelengths between 425-675nm. The lens is sourced from Edmund Optics, a reputable vendor known for their extensive catalog of optical elements.

The lens is constructed from two types of glass, N-BK7 and N-SF5, both from Schott. The use of these materials in a doublet configuration helps to correct chromatic aberration, a common issue in optical systems where different wavelengths of light are focused at different points. This ensures that the lens produces sharp, clear images across the entire visible spectrum.

The lens features a standard coating on both the front and back surfaces. This coating, Edmund Optics' VIS-0 std curve, is designed to enhance the lens's performance within the visible light spectrum. It reduces surface reflections, improving light transmission and enhancing the overall image quality.

The lens's geometry is carefully designed to optimize its performance. It has a thickness of 6.61mm at the edge, with an inner radius of 0mm and an outer radius of 0mm. The first radius of curvature (r1) is 61.47mm, while the second radius (r2) is -44.64mm and the third radius (r3) is -129.94mm. The center thickness of the lens is 6mm, with a center thickness 'a' of 2.5mm.