22-705 75mm Dia. N-BK7 Precision Aspheric Lens; EFL=75mm; NA=0.5 BBAR 425-675nm

This is the 22-705 model from Edmund Optics, a 75mm diameter N-BK7 precision aspheric lens. The lens boasts an effective focal length (EFL) of 75mm and a numerical aperture (NA) of 0.5, making it a versatile choice for various optical applications.

The lens is coated with BBAR (Broadband Anti-Reflection) coating, which is designed to minimize reflection and increase transmission across the visible spectrum, specifically between 425nm and 675nm. This coating enhances the lens's performance in transmitting light, reducing losses, and improving image quality.

The lens's geometry is another notable feature. It has a center thickness of 25.4mm and an edge thickness of 4.99mm. The front and back surfaces of the lens have different radii of curvature (RoC), with the front surface having an RoC of 38.76mm and the back surface being flat. This asymmetry contributes to the lens's aspheric properties, which help correct spherical aberration and other optical aberrations, leading to sharper images and improved overall optical performance.