The Pentax SMC FA 31mm f/1.8 ED AL Limited is a high-performance, fast-aperture prime lens for Pentax K-mount cameras. Key features include:

High-Quality Optics and Performance. When mounted to an APS-C DSLR, it provides a 46mm-equivalent focal length, making it a stellar normal-range lens. Its f/1.8 aperture makes it perfect for low-light shooting, as well as shallow depth-of-field portraiture. The optical build quality is also one of the highest among Pentax lenses, utilizing glass-molded aspherical elements to counteract optical aberrations.

High-Quality Build. As one of Pentax’s Limited-series lenses, it offers a high-quality metal build, complete with manual aperture ring and focus-distance scale. It features a built-in metal lens hood and nine-blade aperture diaphragm, which helps to provide optimum image quality.