The 49-939 is a high-quality achromatic doublet lens, sourced from the renowned optical vendor, Edmund Optics. This lens is specifically designed for use within the visible light spectrum, spanning from 425 to 675 nanometers. The lens boasts a 9mm diameter and an effective focal length of 22.5mm, making it suitable for a wide range of optical applications.
The lens is constructed from two types of Schott glass, N-SSK8 and N-SF56, which are carefully selected to minimize chromatic aberration, a common issue in optical systems. The lens features a standard curve coating on both the front and back surfaces, further enhancing its performance by reducing reflection and improving transmission.
The geometry of the lens is meticulously designed, with a center thickness of 3mm and edge thickness of 3.58mm. The lens curvature is also precisely controlled, with radii of 14.79mm and -12.09mm for the first and second surfaces, respectively, and a -45.72mm radius for the third surface. This complex geometry allows the lens to deliver sharp, clear images with minimal distortion.