The 33-406 is a 40mm diameter, double-convex lens with a focal length of 100mm, sourced from Edmund Optics. This lens is uncoated and features a base shape of a circle, with a geometry that includes an edge thickness of 4.04mm and a center thickness of 8mm. The effective focal length (EFL) is 100mm, while the back focal length (BFL) is 97.33mm. The radii of curvature for the first and second surfaces are 101.98mm and -101.98mm, respectively.
The lens is made of N-BK7 Schott glass, a popular choice for its high refractive index and low dispersion. The wavelength for this lens is 587.6nm. The lens's shape is spherical, a common choice for its ease of manufacturing and good image quality. The coating for this lens is absent, which may result in lower light transmission and potential surface damage. However, uncoated lenses are often chosen for their lower cost and simplicity.