63-704 4 mm Dia. N-BK7/N-SF5 Achromatic Doublet; EFL=12mm VIS 0° 425-675nm

The 63-704 is a high-quality achromatic doublet lens, sourced from Edmund Optics, featuring a 4 mm diameter and an effective focal length of 12 mm. This lens is specifically designed for the visible spectrum, covering wavelengths from 425 to 675 nm.

The lens is composed of two elements, made from N-BK7 and N-SF5 Schott glass, respectively. These materials were chosen for their excellent optical properties, contributing to the lens's overall performance. The lens features a standard anti-reflective coating, denoted as "edm vis-0 std curve" on both the front and back surfaces. This coating enhances the lens's transmission capabilities, reducing unwanted reflections and increasing the overall efficiency of the optical system.

The lens's geometry is carefully designed to provide the best possible performance. The first surface has a radius of curvature of 7.35 mm, while the second surface has a radius of -5.09 mm. The third surface, which is part of the second element, has a radius of -14.6 mm. The center thickness of the lens is 1.8 mm, with a slight asymmetry towards the edge, resulting in a total edge thickness of 2.39 mm.

This lens is a multiplet, meaning it consists of multiple elements. Multiplets are often used in optical systems to correct for chromatic and spherical aberrations, improving the overall image quality. The 63-704 is no exception, offering excellent image quality within its specified spectral range.