This Sigma 30mm F1.4 EX DC HSM is a high quality fixed lens suitable for professional use. The 30mm delivers superior optical performance for any photographer. Employing a large aperture standard lens for digital cameras with a fast 1.4 aperture enables handheld shooting in dim light possible. Its fixed focal length corresponds to the diagonal of the imaging sensor found on most small chip cameras. The lens also functions as a “normal” lens closely replicating the human eye’s field of vision.