37-427 25mm Dia. N-SF6 Precision Aspheric Lens; EFL=18.75mm; NA=0.66 Uncoated

The 37-427 is a high-precision aspheric lens offered by Edmund Optics. This lens, made from N-SF6 Schott glass, boasts a 25mm diameter and a numerical aperture (NA) of 0.66, making it a versatile choice for various optical applications.

The lens's geometry is meticulously designed, featuring an inner radius of 0mm, an outer radius of 0mm, and a thickness edge of 7.97mm. The effective focal length (EFL) is 18.75mm, and the radius of curvature (R1) is 15.098mm. The back focal length (BFL) is 11.27mm, and the thickness at the center is 13.5mm. The lens's conic constant (K1) is -1.169836, with higher-order aspheric terms (K2, K3, etc.) being 0.

The lens's high NA allows for a greater light-gathering capability, making it suitable for high-resolution imaging and other applications where light collection is critical. Despite its high NA, the lens maintains a relatively long focal length, which can be beneficial in applications where a larger working distance is required.

The lens is uncoated, which can be advantageous in certain applications where a specific coating is not required or where cost is a concern. However, it's important to note that uncoated lenses may have higher surface reflections, which can impact overall system performance.