45-136 12.5 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=45mm MgF2 400-700nm

The 45-136 is a high-quality achromatic doublet lens, 12.5 mm in diameter, with an effective focal length (EFL) of 45mm. This lens is sourced from the renowned optical vendor, Edmund Optics, and is available for purchase on their official website. The product link provided is currently valid and indicates that the item is in stock.

The lens is constructed from 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 has a base shape of a circle and features a multiplet geometry. The diameter of the lens is 12.5 mm, and it has a thickness of 3.94 mm at the edge. The inner and outer radii are not specified, indicating that they are not a significant factor in this lens's design. The EFL of 45mm is a critical parameter, as it determines the lens's magnification power.

The lens is coated with MgF2 on both the front and back surfaces. This coating is standard from Edmund Optics and is designed to reduce reflection and increase transmission in the 400-700nm range. The center thickness of the lens is 3.5 mm, and it has a thickness of 1.5 mm at the center 'a' position.