66-315 50 mm Dia. L-BAL35 Precision Aspheric Lens; EFL=37.5mm; NA=0.66 Uncoated

The 66-315 is a high-precision aspheric lens, boasting a 50 mm diameter and a numerical aperture (NA) of 0.66. This lens is sourced from Edmund Optics, a leading provider of optical components. The lens is made from L-BAL35, a material with a high refractive index, making it ideal for a wide range of applications.

The lens has an effective focal length (EFL) of 37.5mm, which is the distance from the lens's principal point to the focal point when the lens is focused at infinity. This EFL makes the lens suitable for use in imaging systems where a moderate focal length is required.

The lens's geometry is another notable feature. It has an inner radius of 0mm and an outer radius of 0mm, indicating a symmetrical design. The lens's thickness at the edge is 3.23mm, while its thickness at the center is 19.4mm. The lens's front diameter is 0mm, and it has a back focal length (BFL) of 25.74mm.

The lens's shape is aspheric, which means it has a non-spherical surface. This design helps to reduce spherical aberration, a common issue in optical systems. The lens's conic constant (k1) is -0.632106, indicating a relatively steep curvature.

Notably, the lens is uncoated. While coatings can enhance a lens's performance by reducing reflection and increasing transmission, an uncoated lens can be advantageous in certain applications, such as when minimal reflection is required.