21-909 12.5mm Dia. UVFS Aspheric Lens; EFL=10mm; NA=0.58 UV-VIS 250-700nm

The 21-909 is a high-performance aspheric lens, designed and manufactured by Edmund Optics. This lens boasts a 12.5mm diameter and a numerical aperture (NA) of 0.58, making it ideal for applications that require a wide field of view and high light-gathering capability.

The lens is made from UV-grade fused silica, a material known for its excellent transparency across the UV-VIS spectrum (250-700nm). This makes the 21-909 particularly suitable for applications in UV-VIS spectroscopy, metrology, and imaging.

The aspheric design of the lens helps to correct spherical aberration, a common issue in traditional spherical lenses. This results in improved image quality, with less distortion and greater sharpness. The lens has an effective focal length (EFL) of 10mm, providing a good balance between field of view and magnification.

The 21-909 is coated with Edmund Optics' standard UV-VIS coating on both the front and back surfaces. This coating enhances the lens's transmission in the UV-VIS range, reduces surface reflections, and provides protection against environmental contaminants.

The lens has a center thickness of 9.5mm and an edge thickness of 3.72mm. The front and back surfaces have radii of curvature of 5.155999934003201mm and 25.219mm, respectively. The lens's geometry is further defined by its conic constant (k1) of -0.555.