MNN206 25.4 mm Dia. N-BK7 Negative Meniscus Lens; EFL=-400mm Uncoated

The MNN206 is a 25.4 mm diameter Negative Meniscus Lens, featuring a concave-convex base shape and a circular geometry. This lens is sourced from WTS Photonics, a reputable vendor in the optical industry. The lens is made from N-BK7 Schott, a high-quality glass material known for its excellent optical properties.

The MNN206 has a center thickness of 3.5 mm and an edge thickness of 3.9 mm, providing a robust and durable structure. The effective focal length (EFL) of this lens is -400mm, making it suitable for applications that require a negative focal length. The first radius of curvature (R1) is 235.5 mm, while the second radius (R2) is 109.65 mm, indicating a significant curvature that contributes to its negative meniscus shape.

The lens's back focal length (BFL) is -397.33 mm, which is marginally shorter than its EFL. This discrepancy is due to the lens's concave-convex geometry, where the concave side is closer to the light source, resulting in a shorter BFL than EFL. The lens does not have any inner or outer radius, indicating a uniform curvature throughout its geometry.

The MNN206 operates at a wavelength of 588 nm, making it suitable for applications that utilize yellow light. It is uncoated, meaning it does not have any anti-reflective or other surface coatings. This may result in higher reflectivity and lower transmission compared to coated lenses, but it also means that the lens is less susceptible to damage from environmental factors or mishandling.