32-915 18 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=80mm MgF2 400-700nm

This is a high-quality achromatic doublet lens from the renowned optical vendor, Edmund Optics. The lens, catalog number 32-915, is a multiplet type with a base shape of a circle. It has a diameter of 18 mm and an effective focal length (EFL) of 80 mm, making it suitable for a wide range of optical applications.

The lens is composed of two types of glass, N-BK7 and N-SF5, both from Schott. This combination is used to correct chromatic aberration, a common issue in optical systems where different wavelengths of light are focused at different points. The achromatic design ensures that the lens focuses both red and blue light at the same point, providing sharper images.

The lens features a standard MgF2 coating on both the front and back surfaces. This coating reduces reflection and increases transmission, particularly in the 400-700 nm range. The thickness of the lens varies, with an edge thickness of 6.27 mm and a center thickness of 5 mm. The center thickness reduces to 2.5 mm at the lens's edge 'a'.

The lens's geometry is also noteworthy. It has an inner radius of 0 and an outer radius of 0, indicating a symmetrical design. The radii of curvature are r1 = 49.67 mm, r2 = -34.73 mm, and r3 = -100.11 mm.