69-142 25mm Dia. L-BAL35 Calibration Grade Aspheric Lens; EFL=25mm; NA=0.5 Uncoated

This is the 69-142 25mm Dia. L-BAL35 Calibration Grade Aspheric Lens, a high-quality optical component sourced from Edmund Optics. The lens is designed with a base shape of Circular and is fabricated from the L-BAL35 material, a type of optical glass developed by Ohara.

The lens has a diameter of 25mm and a numerical aperture (NA) of 0.5, making it suitable for a wide range of optical applications. The NA is a measure of the light-gathering ability of the lens, and a value of 0.5 indicates a moderate to high light-gathering capacity.

The lens features an effective focal length (EFL) of 25mm, which is the distance over which the lens focuses light. This is a crucial parameter in lens selection, as it directly impacts the magnification and field of view of the optical system.

The lens is uncoated, meaning it does not have any anti-reflective coatings. While coatings can enhance the performance of a lens by reducing unwanted reflections, an uncoated lens can be advantageous in certain applications where such reflections are not a concern.

The geometry of the lens is defined by several parameters, including the inner and outer radii, thickness at the edge and center, and the back focal length (BFL). The BFL is the distance between the lens and the image plane when the lens is focused at infinity.

The lens also has aspheric surfaces, which are non-spherical surfaces designed to reduce various optical aberrations. This makes the lens particularly suitable for high-precision applications where image quality is paramount.